Question

afla aria bazei, laterala, totala si volumul unei piramide hexagonale de 5 dm latura bazei si muchia laterala de 10 dm

Answer 1

a)Ab=3l²√3/2=3·5²√3/2=3·25√3/2=75√3/2dm²

b)In ΔVAM ,m(∡M)=90°→VM²=AV²-AM²

VM²=10²-2,5²=100-6,25=93,75

VM=√93,75=2,5√15

Al=Pb·ap/2=6·5·2,5√15/2=3·5·2,5√15=17,5√15dm²

c)At=Ab+Al=75√3/2+17,5√15=(75√3+45√15/2)dm²

d)apotema bazei=l√3/2=5√3/2

InΔVMO ,m(∡O)=90°→VO²=VM²-MO²=(2,5√15)²-(5√3/2)²=93,75-75/4=

=375-75/4=300/4

VO=√300/√4=10√3/2

V=Ab·h/3=(75√3/2·10√3/2):3=375·3/3=375 dm³