Dane:
V=3\sqrt3cm^3
P_b=18cm^2
Obliczyć:
P_c
V=\frac{a^2\sqrt3}{4}*H
\frac{a^2\sqrt3}{4}*H=3\sqrt3/:\sqrt3
\frac{a^2H}{4}=3
a^2H=12 (*)
P_b=3aH
3aH=18/:3a
H=\frac{6}{a}
podstawiam do (*)
a^2*\frac{6}{a}=12
6a=12
a=2
H=6:2=3
P_p=2*\frac{a^2\sqrt3}{4}=2*\frac{4\sqrt3}{4}=2\sqrt3(cm^2)
P_c=P_p+P_b=2\sqrt3+18=2(\sqrt3+9)(cm^2)