Răspuns:
Explicație pas cu pas:
4.
D²=L²+l² 10²=6² +L² ⇒L=8 cm P=2(6+8)=2×14=28 cm
5.
D=20 cm si sin 30°=l/D l=D/2=10 cm
L²=D²-l²=400-100=300 L=10√3cm
6.
Se formeaza ΔAOB AO=4 cm si BO=3cm
l²=AO²+OB²=25 l=5 cm
P=4l=20 cm
7. P=40 cm l=8 cm
AO=4 cm BO²=l²-AO²=8²-4²=4×12 BO=4√3 cm
BD=8√3 cm
8/ in AOB ∡BAO=30° BO=5 cm
⇒BO=l/2 l=5cm P=4l=20 cm
11/
l1=l2=10 cm
l mijl=12 cm=(B+b)/2
P=2l1+2lmijl=2×20+24=64 cm
