Question

Vă rog, ajutați-mă la exercițiile astea...
Dau coroana, promit!

Answer 1

1.

Ap²=m²-(L/2-l/2)²=17²-(20/2-4/2)²=17²-(10-2)²=289-64=225=>Ap=√225=15 cm

H²=Ap²-(L/2-l/2)²=15²-8²=225-64=161=>H=√161 cm

Al=(P+p)Ap/2=(4L+4l)*15/2=(80+16)15/2=48*15=720 cm²

At=Al+Ab+A_B

Ab=l²=4²=16 cm²

A_B=L²=20²=400 cm

At=720+16+400=1136 cm²

Ap-> apotema  trunchiului de piramida

2.

Ab=l²√3/4=6²√3/4=9√3 cm²

A_B=L²√3/4=12²√3/4=36√3 cm²

Ap²=H²+(L/2-l/2)²=13+(6-3)²=13+9=22 =>Ap=√22 cm

m²=Ap²+(L/2-l/2)²=22+9=31=>m=√31 cm

Al=(Pb+P_B)Ap/2=(3l+3L)√22/2=(12+36)√22/2=24√22 cm²