Răspuns:
Explicație pas cu pas:
80cm•5cm/2
400/2
Aria =200 cm
2.aria trapez= (b+B)•h/2
(10+60cm)•30/2
70•30/2
2100/2
1050cm
3.c1•c2/2
9•12/2
108/2
54cm
5.P=2l+2L
L=3l
P=2l+3l
P=5l
40=5l
l=40/5
l=8
L=8•3
L=24
6.m<A=60° , ABCD=romb. =>ab=bc=cd=da
P=4l
16=4l
l=4cm
aria =4•4radical din 3/2
aria=8 radical din 3
7.A=c1•c2/2
m<=45°=> triunghi isoscel=> c1=c2=26
A=26•26/2
A=338
8. A=latura la a doua
P=4l
48=4l
l=12
A=12 la a doua
A=144
