1 \startsection[reference=seccio:figures-semblants, title={Figures semblants}]
3 \startsubject[title={Preguntes}]
5 Podeu veure què és la semblança (secció~\in[seccio:teoria-semblança]).
7 \startexercici[reference=exer:smileys] Quines d'aquestes figures vos pareixen semblants (figura~\in[fig:smiley-quins-son-semblants]):
9 \startplacefigure[location={split, here}, reference=fig:smiley-quins-son-semblants, title={Smilies}]
10 \bTABLE[frame=off,align=middle,split=yes, width=fit]
13 \externalfigure[figs/proporcionalitat-geometrica-figs-smiley-wiki.png][scale=100]
18 \externalfigure[figs/proporcionalitat-geometrica-figs-smiley-wiki-menys-alt.png][scale=150]
23 \externalfigure[figs/proporcionalitat-geometrica-figs-smiley-wiki.png][scale=200]
30 \mirror{\externalfigure[figs/proporcionalitat-geometrica-figs-smiley-wiki-menys-alt.png][scale=200]}
35 \externalfigure[figs/proporcionalitat-geometrica-figs-smiley-wiki.png][scale=100,orientation=180]
40 \mirror{\externalfigure[figs/proporcionalitat-geometrica-figs-smiley-wiki.png][scale=150]}
47 \rotate[rotation=180]{\mirror{\externalfigure[figs/proporcionalitat-geometrica-figs-smiley-wiki.png][scale=100]}}
52 \externalfigure[figs/proporcionalitat-geometrica-figs-smiley-wiki-perspectiva.png][scale=150]
57 \mirror{\externalfigure[figs/proporcionalitat-geometrica-figs-smiley-wiki.png][scale=100]}
64 \externalfigure[figs/proporcionalitat-geometrica-figs-smiley-wiki-perspectiva.png][scale=200]
69 \rotate[rotation=60]{\externalfigure[figs/proporcionalitat-geometrica-figs-smiley-wiki-perspectiva.png][scale=150]}
74 \mirror{\externalfigure[figs/proporcionalitat-geometrica-figs-smiley-wiki-menys-alt.png][scale=250]}
82 Feis una taula on trobeu totes les figures semblants entre elles.
85 En aquest punt, seria interessant mirar la secció~\in[seccio:teoria-figures-semblants].
87 \startexercici[reference=exer:semblança-dos-rectangles] Són semblants els rectangles següents? En cas de ser-ho, quina és la seva raó de semblança?
89 \startplacefigure[location={force,none}, reference=fig:exercici-49-toomates, title={Possibles rectangles semblants}]
90 \bTABLE[frame=off,align=middle]
92 \bTD {\starttikzpicture[scale=1]
93 \draw[very thick] (0,0) -- (3,0) -- (3,2) -- (0,2) -- cycle;
94 \draw (0, 1) node[anchor=east] {$2 \unit{centi meter}$};
95 \draw (1.5, 0) node[anchor=south] {$3 \unit{centi meter}$};
97 \startscope[shift={(5,0)}]
98 \draw[very thick] (0,0) -- (6,0) -- (6,4) -- (0,4) -- cycle;
99 \draw (0, 2) node[anchor=west] {$4 \unit{centi meter}$};
100 \draw (3, 0) node[anchor=south] {$6 \unit{centi meter}$};
110 \startexercici[reference=exer:prendre-mides-rectangles] Preneu mides amb un regle dels rectangles següents i digueu si són semblants.
112 \startplacefigure[location={force,none}, reference=fig:exercici-50-toomates, title={Possibles rectangles semblants}]
113 \bTABLE[frame=off,align=middle]
115 \bTD {\starttikzpicture[scale=1]
116 \draw[very thick] (0,0) -- (3.9,0) -- (3.9,1.7) -- (0,1.7) -- cycle;
118 \startscope[shift={(5,0)}]
119 \draw[very thick] (0,0) -- (9.4,0) -- (9.4,4.4) -- (0,4.4) -- cycle;
128 \startexercici[reference=exer:modificació-figures] Modifiqueu aquestes figures per a què siguin semblants.
130 \startplacefigure[location={force,none}, reference=fig:exercici-47-toomates, title={Modificació de figures no semblants}]
131 \bTABLE[frame=off,align=middle]
134 \starttikzpicture[scale=0.5]
135 \draw[step=1cm,gray!30, help lines, very thin] (-1,0) grid (8,10);
137 \startscope[shift={(0,0)}]
138 \filldraw[fill=green!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (1,2) -- (1,3) -- (1,4) -- (1,5) -- (0,5) -- (0, 4) -- (0, 3) -- (0, 2) -- (0,1);
141 \startscope[shift={(3,-1)},scale=2]
142 \filldraw[fill=orange!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (1,2) -- (1,3) -- (1,4) -- (1,4.5) -- (0,4.5) -- (0, 4) -- (0, 3) -- (0, 2) -- (0,1);
147 \starttikzpicture[scale=.8]
148 \draw[step=.5cm,gray, very thin] (0,0) grid (10,7);
157 \startexercici[reference=exer:quines-són-semblants] Quines figures són semblants? Calculeu la seva raó de semblança.
159 \startplacefigure[location={force,none}, reference=fig:exercici-43-toomates, title={Possibles triangles semblants}]
160 \bTABLE[frame=off,align=middle]
163 \starttikzpicture[scale=0.70]
164 \startscope[shift={(0,0)}]
165 \filldraw[fill=yellow!50,very thick] (0, 0) -- (4, 0) -- (4, 6) -- (2, 8) -- (0, 6) -- cycle;
168 \startscope[shift={(6,0)}]
169 \filldraw[fill=green!50,very thick] (0, 0) -- (2, 0) -- (2, 6) -- (1, 7) -- (0, 6) -- cycle;
172 \startscope[shift={(10,0)}]
173 \filldraw[fill=blue!50,very thick] (0, 0) -- (4, 0) -- (4, 3) -- (2, 4) -- (0, 3) -- cycle;
176 \startscope[shift={(16,0)}]
177 \filldraw[fill=red!50,very thick] (0, 0) -- (2, 0) -- (2, 3) -- (1, 4) -- (0, 3) -- cycle;
181 \draw[step=1cm,gray!30, help lines, very thin] (0,0) grid (18,8);
183 % tornar a fer els contorns
184 \startscope[shift={(0,0)}]
185 \draw[very thick] (0, 0) -- (4, 0) -- (4, 6) -- (2, 8) -- (0, 6) -- cycle;
188 \startscope[shift={(6,0)}]
189 \draw[very thick] (0, 0) -- (2, 0) -- (2, 6) -- (1, 7) -- (0, 6) -- cycle;
192 \startscope[shift={(10,0)}]
193 \draw[very thick] (0, 0) -- (4, 0) -- (4, 3) -- (2, 4) -- (0, 3) -- cycle;
196 \startscope[shift={(16,0)}]
197 \draw[very thick] (0, 0) -- (2, 0) -- (2, 3) -- (1, 4) -- (0, 3) -- cycle;
207 \startexercici Feis una figura el triple de gran del dibuix que hi ha dibuixat.
209 \startplacefigure[location={here,none}, reference=fig:exercici-peix-toomates, title={Construcció d'una figura semblant al peix}]
210 \bTABLE[frame=off,align=middle]
213 \starttikzpicture[scale=.8]
214 \draw[step=.5cm,gray, very thin, help lines] (0,0) grid (20,11);
215 \draw[line width=2pt, color=blue!80!black] (0.5, 9) -- (1,9.5) -- (1.5, 10) -- (3.5,10) -- (4,9.5) -- (4.5,9)-- (5,9.5) -- (5.5,10) -- (5.5,8) -- (4.5, 9) -- (3.5,8) -- (1.5,8) -- (0.5, 9);
216 \draw[line width=2pt, color=blue!80!black] (1.5, 9) -- (2,9) -- (2,9.5) -- (1.5,9.5) -- (1.5, 9);
223 La figura resultant és semblant? Per què?
226 \startexercici Dibuixeu dos triangles la raó de semblança dels quals sigui $1/2$
229 \startexercici Si els costats d'un triangle mesuren respectivament 12, 5, i 7,5 \unit{centi meter}, quant mesuraran els costats d'un altre triangle semblant si la raó de semblança del segon respecte del primer és $1/3$ ? I si la raó de semblança fos de 3?
232 \startexercici Dibuixeu dos triangles equilàters de 5 i 8 \unit{centi meter}\space de costat, respectivament.
233 \startitemize[a,packed]
235 \item En cas afirmatiu, calculeu la raó de semblança
239 \startexercici Els costats d'un triangle fan 9, 12 i 15 \unit{centi meter}, respectivament. Trobeu els costats d'un altre triangle semblant sabent que el costat més gran fa 24 \unit{centi meter}.
242 \startexercici[reference=exer:coca-coles] Trobeu quines llaunes d'aquests refrescs de cola són o no semblants (figura~\in[fig:coca-coles-toomates]). Trobeu la raó de semblança de cadascuna.
244 \startplacefigure[location={force, split}, reference=fig:coca-coles-toomates, title={Imatges de llaunes de cola}]
245 \bTABLE[frame=off,align=middle, split=yes, width=fit]
248 \externalfigure[figs/proporcionalitat-geometrica-figs-coca-cola.jpg][scale=2000]
253 \externalfigure[figs/proporcionalitat-geometrica-figs-coca-cola-5.jpg][scale=2000]
258 \externalfigure[figs/proporcionalitat-geometrica-figs-coca-cola-6.jpg][wfactor=100,hfactor=200]
266 \externalfigure[figs/proporcionalitat-geometrica-figs-coca-cola-2.jpg][scale=2700]
271 \externalfigure[figs/proporcionalitat-geometrica-figs-coca-cola-5.jpg][scale=1500]
276 \externalfigure[figs/proporcionalitat-geometrica-figs-coca-cola-6.jpg][wfactor=120,hfactor=60]
283 \externalfigure[figs/proporcionalitat-geometrica-figs-coca-cola-8.jpg][scale=3000]
288 \externalfigure[figs/proporcionalitat-geometrica-figs-coca-cola-4.jpg][scale=3200]
298 \startexercici A quina escala s'ha fet la reproducció de la lletra \quotation{T} en cada cas?
300 \startplacefigure[location={force,none}, reference=fig:exercici-construccio-figures-rao, title={Identificació de figures semblants}]
301 \bTABLE[frame=off,align=middle]
303 \bTD[align={middle,lohi}]
305 \startcombination[1*1]
306 {\starttikzpicture[scale=.4]
308 \draw[step=1cm,gray, help lines, very thin] (-1,0) grid (5,5);
310 \startscope[shift={(0,3)}]
311 \draw[color=blue,line width=2mm] (0, 1) -- (4, 1);
312 \draw[color=blue,line width=2mm] (2, 1) -- (2, -2);
321 \bTD[align={middle,lohi}]
323 \startcombination[1*1]
324 {\starttikzpicture[scale=.4]
326 \draw[step=1cm,gray, help lines, very thin] (-1,0) grid (13,11);
328 \startscope[shift={(0,7)},scale=3]
329 \draw[color=blue,line width=2mm] (0, 1) -- (4, 1);
330 \draw[color=blue,line width=2mm] (2, 1) -- (2, -2);
339 \bTD[align={middle,lohi}]
341 \startcombination[1*1]
342 {\starttikzpicture[scale=.4]
344 \draw[step=1cm,gray, help lines, very thin] (-1,0) grid (4,6);
346 \startscope[shift={(1,1)},rotate around={90:(0,0)}]
347 \draw[color=blue,line width=2mm] (0, 1) -- (4, 1);
348 \draw[color=blue,line width=2mm] (2, 1) -- (2, -2);
357 \bTD[align={middle,lohi}]
359 \startcombination[1*1]
360 {\starttikzpicture[scale=.4]
362 \draw[step=1cm,gray, help lines, very thin] (-1,0) grid (7,10);
364 \startscope[shift={(4,9)},scale=2,rotate around={-90:(0,0)}]
365 \draw[color=blue,line width=2mm] (0, 1) -- (4, 1);
366 \draw[color=blue,line width=2mm] (2, 1) -- (2, -2);
383 \startexercici[reference=exer:fotografia-i-marc] Una fotografia de 9 cm d'amplada i 6 cm d'alçada té al voltant un marc de 2,5 cm d'ample. Són semblants els rectangles interior i exterior del marc?\footnote{Hi ha un problema molt semblant (exercici 14) a la secció {\em Problemas de Geometría} del llibre {\em Problemates. Colección de problemas matemáticos para todas las edades} de Lluís Segarra. Editorial Graó. {\char"00A9} 2008 Lluís Segarra i Editorial Graó.}
386 \startexercici Els costats d'un triangle fan 18, 24 i 32 \unit{centi meter}, respectivament. Trobeu els costats d'un altre triangle semblant sabent que el més petit fa 24 \unit{centi meter}.
389 \startexercici Quant faran els costats i el perímetre d'un triangle semblant a un altre de costats 36, 42 i 54 \unit{milli meter}, respectivament, si la raó de semblança és de 5?
393 \startexercici Quins parells de figures són semblants? Per què?
395 \startplacefigure[location={force}, reference=fig:exercici-parells-semblants, title={Exemple d'identificació de figures semblants}]
396 \bTABLE[frame=off,align=middle]
398 \bTD[align=middle] {\starttikzpicture[scale=.4]
400 \draw[step=1cm,gray!30, help lines, very thin] (-1,0) grid (8,10);
402 \startscope[shift={(0,0)}]
403 \filldraw[fill=green!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (1,2) -- (1,3) -- (1,4) -- (1,5) -- (0,5) -- (0, 4) -- (0, 3) -- (0, 2) -- (0,1);
406 \startscope[shift={(3,-1)},scale=2]
407 \filldraw[fill=red!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (1,2) -- (1,3) -- (1,4) -- (1,5) -- (0,5) -- (0, 4) -- (0, 3) -- (0, 2) -- (0,1);
410 \draw (1, 0) node[fill=white] {$A$};
411 \draw (5, 0) node[fill=white] {$B$};
419 \startframedtext[width=.6\textwidth]
422 \text{raó de l'amplada} = \frac{\text{amplada de $B$}}{\text{amplada de $A$}} = \frac{4}{2} = 2
425 \text{raó de l'altura} = \frac{\text{altura de $B$}}{\text{altura de $A$}} = \frac{8}{4} = 2
429 \startalignment[middle]
430 {\sc Són iguals} $\Rightarrow$ {\sc Són semblants} $\Rightarrow$ $A \cong B$
440 \startplacefigure[location={force, split}, reference=fig:exercici-parells-semblants-bis, title={Identificació de figures semblants}]
441 \bTABLE[frame=off,align=middle, split=yes]
443 \bTD[align={middle,lohi}] {\starttikzpicture[scale=.4]
445 \draw[step=1cm,gray, help lines, very thin] (-1,0) grid (6,6);
447 \startscope[shift={(0,0)}]
448 \filldraw[fill=green!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (1,2) -- (1,3) -- (1,4) -- (1,5) -- (0,5) -- (0, 4) -- (0, 3) -- (0, 2) -- (0,1);
451 \startscope[shift={(3,0.5)},scale=.5]
452 \filldraw[fill=red!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (1,2) -- (1,3) -- (1,4) -- (1,5) -- (0,5) -- (0, 4) -- (0, 3) -- (0, 2) -- (0,1);
455 \draw (1, 0) node[fill=white] {$C$};
456 \draw (3.5, 0) node[fill=white] {$D$};
463 \startframedtext[width=.25\textwidth,height=4cm,frame=off,topframe=on,bottomframe=on]
467 \bTD[align=middle] {\starttikzpicture[scale=.4]
469 \draw[step=1cm,gray, help lines, very thin] (-1,0) grid (8,10);
471 \startscope[shift={(0,0)}]
472 \filldraw[fill=green!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (1,2) -- (1,3) -- (1,4) -- (1,5) -- (0,5) -- (0, 4) -- (0, 3) -- (0, 2) -- (0,1);
475 \startscope[shift={(3,0)},scale=2]
476 \filldraw[fill=red!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (1,2) -- (1,3) -- (1,4) -- (0,4) -- (0, 3) -- (0, 2) -- (0, 1);
479 \draw (1, 0) node[fill=white] {$E$};
480 \draw (5, 1) node[fill=white] {$F$};
485 \startframedtext[width=.25\textwidth,height=4cm,frame=off,topframe=on,bottomframe=on]
491 \bTD[align=middle] {\starttikzpicture[scale=.4]
493 \draw[step=1cm,gray, help lines, very thin] (-1,0) grid (9,12);
495 \startscope[shift={(0,0)}]
496 \filldraw[fill=green!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (1,2) -- (1,3) -- (1,4) -- (1,5) -- (0,5) -- (0, 4) -- (0, 3) -- (0, 2) -- (0,1);
499 \startscope[shift={(3,-1.5)},scale=2.5]
500 \filldraw[fill=red!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (1,2) -- (1,3) -- (1,4) -- (1,5) -- (0,5) -- (0, 4) -- (0, 3) -- (0, 2) -- (0,1);
503 \draw (1, 0) node[fill=white] {$G$};
504 \draw (5.5, 0) node[fill=white] {$H$};
511 \startframedtext[width=.25\textwidth,height=4cm,frame=off,topframe=on,bottomframe=on]
515 \bTD[align=middle] {\starttikzpicture[scale=.5]
517 \draw[step=1cm,gray, help lines, very thin] (-1,0) grid (7,7);
519 \startscope[shift={(0,0)}]
520 \filldraw[fill=green!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (1,2) -- (1,3) -- (1,4) -- (1,5) -- (0,5) -- (0, 4) -- (0, 3) -- (0, 2) -- (0,1);
523 \startscope[shift={(6,7)},rotate around={180:(0,0)}]
524 \filldraw[fill=red!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (3,1) -- (3,2) -- (2,2) -- (1,2) -- (1,3) -- (1,4) -- (1,5) -- (1,6) -- (0,6) -- (0, 5) -- (0, 4) -- (0, 3) -- (0,2) -- (0,1);
527 \draw (1, 0) node[fill=white] {$I$};
528 \draw (5, 0) node[fill=white] {$J$};
533 \startframedtext[width=.25\textwidth,height=4cm,frame=off,topframe=on,bottomframe=on]
539 \bTD[align=middle] {\starttikzpicture[scale=.4]
541 \draw[step=1cm,gray, help lines, very thin] (-1,0) grid (9,9);
543 \startscope[shift={(0,0)}]
544 \filldraw[fill=blue!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (2,3) -- (2,4) -- (0,1);
547 \startscope[shift={(12,2)},scale=3,rotate around={90:(0,0)}]
548 \filldraw[fill=yellow!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (2,3) -- (2,4) -- (0,1);
551 \draw (1, 0) node[fill=white] {$K$};
552 \draw (5.5, 3) node[fill=white] {$L$};
557 \startframedtext[width=.25\textwidth,height=4cm,frame=off,topframe=on,bottomframe=on]
561 \bTD[align=middle] {\starttikzpicture[scale=.4]
563 \draw[step=1cm,gray, help lines, very thin] (-1,0) grid (8,8);
565 \startscope[shift={(0,-1)},scale=2]
566 \filldraw[fill=blue!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (2,3) -- (2,4) -- (0,1);
569 \startscope[shift={(4,4)},scale=1,rotate around={-90:(0,0)}]
570 \filldraw[fill=yellow!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (2,3) -- (2,4) -- (0,1);
573 \draw (2, 0) node[fill=white] {$M$};
574 \draw (6, 1) node[fill=white] {$N$};
579 \startframedtext[width=.25\textwidth,height=4cm,frame=off,topframe=on,bottomframe=on]
585 \bTD[align=middle] {\starttikzpicture[scale=.4]
587 \draw[step=1cm,gray, help lines, very thin] (-1,-2) grid (10,9);
589 \startscope[shift={(0,1)},rotate around={-90:(0,0)}]
590 \filldraw[fill=blue!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (2,3) -- (2,4) -- (0,4) -- (0,1);
593 \startscope[shift={(12,2)},scale=3,rotate around={90:(0,0)}]
594 \filldraw[fill=yellow!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (2,3) -- (2,4) -- (0,4) -- (0,1);
597 \draw (2.5, 0) node {{\it Ñ}};
598 \draw (4.5, 4.5) node {$O$};
603 \startframedtext[width=.25\textwidth,height=4cm,frame=off,topframe=on,bottomframe=on]
607 \bTD[align=middle] {\starttikzpicture[scale=.4]
609 \draw[step=1cm,gray,help lines, very thin] (-1,0) grid (8,10);
611 \startscope[shift={(2,6)},rotate around={180:(0,0)}]
612 \filldraw[fill=blue!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (2,3) -- (2,4) -- (1,4) -- (1,5) -- (0,5) --(0,4) -- (0,1);
615 \startscope[shift={(3,-1)},scale=2,rotate around={0:(0,0)}]
616 \filldraw[fill=yellow!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,2) -- (2,3) -- (2,4) -- (1,4) -- (1,5) -- (0,5) --(0,4) -- (0,1);
620 \draw (1, 5.5) node[fill=white, anchor=south] {$P$};
621 \draw (5, 0.5) node[fill=white, anchor=north] {$Q$};
626 \startframedtext[width=.25\textwidth,height=4cm,frame=off,topframe=on,bottomframe=on]
635 \startexercici Modifiqueu els rectangles següents per a què siguin semblants
638 \startplacefigure[location={force,split}, reference=fig:exercici-modificacio-figures semblants, title={Rectangles que poden ser semblants}]
639 \bTABLE[frame=off,align=middle, split=yes]
641 \bTD[align=middle] {\starttikzpicture[scale=.4]
643 \draw[step=1cm,gray, help lines, very thin] (-1,0) grid (8,12);
645 \startscope[shift={(0,0)}]
646 \filldraw[fill=green!50,very thick] (0, 1) -- (1, 1) -- (2, 1) -- (2,5) -- (1,5) -- (0,5) -- (0,1);
649 \startscope[shift={(3,0)}]
650 \filldraw[fill=red!50,very thick] (0, 1) -- (4, 1) -- (4,8) -- (0,8) -- (0,1);
659 {\starttikzpicture[scale=.4]
661 \draw[step=1cm,gray, very thin] (0,0) grid (15,12);
667 \bTD[align=middle] {\starttikzpicture[scale=.4]
669 \draw[step=1cm,gray, help lines, very thin] (-1,0) grid (8,12);
671 \startscope[shift={(-1,3)},rotate around={-90:(0,0)}]
672 \filldraw[fill=green!50,very thick] (0, 1) -- (2, 1) -- (2,7) -- (0,7) -- (0,1);
675 \startscope[shift={(0,3.5)},rotate around={0:(0,0)},scale=.5]
676 \filldraw[fill=red!50,very thick] (0, 1) -- (2, 1) -- (2,7) -- (0,7) -- (0,1);
685 {\starttikzpicture[scale=.4]
687 \draw[step=1cm,gray, very thin] (0,0) grid (15,12);
693 \bTD[align=middle] {\starttikzpicture[scale=.4]
695 \draw[step=1cm,gray, help lines, very thin] (-1,0) grid (9,12);
697 \startscope[shift={(0,0)}]
698 \filldraw[fill=green!50,very thick] (0, 1) -- (1, 1) -- (3, 1) -- (3,5) -- (1,5) -- (0,5) -- (0,1);
701 \startscope[shift={(4,0)}]
702 \filldraw[fill=red!50,very thick] (0, 1) -- (4, 1) -- (4,8) -- (0,8) -- (0,1);
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723 \startexercici Calculeu les dimensions d'un rectangle la diagonal del qual fa 75 \unit{centi meter}\space si és semblant a un altre rectangle els costats del qual fan 36 i 48 \unit{meter}.
726 \startexercici Indiqueu si són semblants dos triangles amb les mesures següents: els costats de l'un fan 10 \unit{centi meter}, 7 \unit{centi meter}\space i 6 \unit{centi meter}, i els de l'altre, 20 \unit{centi meter}, 14 \unit{centi meter}\space i 32 \unit{centi meter}.
732 \startsubject[title={Solucions}]
734 \startitemize[1][distance=0.5cm]