Question

The height of a cone is 15 cm. If its volume is 1570 cm3, find the diameter of its base. [Use $\pi$ = 3.14]

Answer 1

Height (h) of cone = 15 cm
Let the radius of the cone be r.
Volume of cone = 1570 cm3
$\frac{1}{3}\pi$r²h = 1570 cm³

r² =$\frac{\text{ (1570 cm³ × 3) }}{ \pi h}$

r² = $\frac{\text{(1570 cm³ × 3) }}{\text{ (3.14 × 15 cm) }}$= 100 cm²

r = $\sqrt{100}$ cm²
r = 10 cm
Therefore, the radius of the base of cone is 10 cm.