Question

If a prism of base $9cm\times 7cm$ can store $819cc$ of water, find its total surface area.

Answer 1

Length of the prism $l=9cm$
Breadth of the prism $b=7cm$

Storing capacity of the prism $=$ Volume of the prism $=l\times b\times h$, , where $h$ is the height of the prism.
$⟹819=9\times 7\times h$
$⟹819=63\times h$
$⟹h=\frac{819}{63}=13cm$

Total Surface Area of the prism $=2(lh+bh+lb)$
$=2(9\times 13+7\times 13+9\times 7)$
$=2(117+91+63)$
$=2\times 271=542c{m}^2$