Question

Cum se afla lungimea inaltimii unei piramide triunghiulare si lungimea apotemei unei piramide patrulatere? :)

Answer 1

Al=260
At=360
At=Al+Ab   ⇒Ab=At-Al=360-260=100

Ab=l²   ⇒l²=100  ⇒l=10

Al=Pb*ap/2
Pb=4l=4*10=40
260=40*ap/2
ap=260*2/40
ap=26/2
ap=13
VM-ap
M∈BC,  BM=MB=BC/2= 10/2=5
AC intersectat BD={O} -centrul bazei
OM=BC/2= 10/2=5

VO_|_(ABC)
OM inclus (ABC)   ⇒VO_|_OM  ⇒mas<VOM=90
ΔVOM   ⇒VO²=VM²-OM²=13²-5²=169-25=144   ⇒VO=12   VO-h

V=Ab*h/3= 260*12/3=  260*4=1040 cm³