Find the volume of the right circular cone with radius 3.5 cm, height 12 cm.

Given,

Radius of the cone (r) = 3.5 cm

Height of the cone (h) = 12 cm

By formula,

Volume of the cone (V) = $\dfrac{1}{3}πr^2h$

Substituting values we get :

$V = \dfrac{1}{3} \times \dfrac{22}{7} \times (3.5)^2 \times 12 \\[1em] = \dfrac{1}{3} \times \dfrac{22}{7} \times 12.25 \times 12 \\[1em] = 22 \times 1.75 \times 4 \\[1em] = 154 \text{ cm}^3.$

Hence, volume of cone = 154 cm³.