1.[tex] P_{curte}=2(L+l)=100m \\ L=l+10 \\ 2(L+l)=2(l+10+l)=2(2l+10)=4l+20=100 \\ 4l=80;l=20m;L=l+10=20+10=30m \\ A_{curte}=L*l=20*30=600 m^{2} \\ [/tex]
a)[tex]A_{flori}=A_{curte}* \frac{35}{100}=600 * \frac{35}{100}=6*35=210 m^{2} [/tex]
b)[tex]A_{iarba}=A_{curte}-A_{flori}=600-210=390 m^{2}[/tex]
2.[tex]l= \frac{80}{100}*L= \frac{80}{100}*15= \frac{1200}{100}=12m \\ A_{patrat}= l_{patrat} ^{2} = 2^{2}=4 m^{2} \\ [/tex]
a)[tex]A_{flori}=3*A_{patrat}=3*4=12m^{2}[/tex]
b)[tex]A_{gradina}=L*l=15*12=180 m^{2} \\ A_{pietris}=A_{gradina}-A_{flori}} =180-12=168m^{2}[/tex]
c)[tex] P_{gradina} =2*(L+l)=2*(15+12)=2*27=54m \\ Pret_{gard}= P_{gradina}*12,4lei/m=54m*12,4lei/m=669,6lei[/tex]
3.[tex]L=3*l \\ A_{terasa} =L*l=3l*l=3l ^{2} =48 m^{2} \\ l ^{2} =48 m^{2} :3=16 m^{2} \\ l=4m \\ L=3l=3*4=12m \\ P_{terasa} =2*(L+l)=2*(4+12)=2*16=32m[/tex]