Question

Find the volume of a frustum cone, whose base and upper area of a circle is $40c{m}^2$ and $40$ $c{m}^2$. The height of the cone is $12$ cm.

• A. $380$ $c{m}^3$
• B. $480$ $c{m}^3$
• C. $580$ $c{m}^3$
• D. $680$ $c{m}^3$

Answer 1

Answer: (B)

$480$ $c{m}^3$

Volume of frustum $=\frac{1}{3}(A_1+A_2+\sqrt{A_1{A}_2})\times h$

$=\frac{1}{3}\times (40+40+\sqrt{40\times 40})\times 12$

$=(80+40)\times 4=120\times 4$

$=480$${cm}^3$