Question

Aflati aria totala si volumul unei piramide patrulatere regulate cu aria de 64cm la 2 ,apotema piramidei de 9 cm si inaltimea de 10 cm

Answer 1

Ab=aria bazei=$l^{2}$ ; Al=arie laterala= $\frac{Pb*ap}{2}$; At=arie totala=Al+Ab; ap=apotema piramidei; Pb=perimetrul bazei=4l; h=inaltimea; V=volumul=$\frac{Ab*h}{3}$

 Ab=Apatrat=$l^{2}$ => $l^{2}$=64cm la 2 => l=8 cm => Pb=4l=4*8=32cm

Al= $\frac{32*9}{2}= \frac{288}{2}=144 cm^{2}$

At=144+64=208$cm^{2}$

V=64*10/3=640/3=213,33cm³