Question

The radius (in cm) of the largest right circular cone that can be cut out from a cube of edge $4.2cm$ is

(a) $2.1cm$ (b) $4.2cm$ (c) $8.4cm$ (d) $1.05cm$

Answer 1

Correct option is (a) $2.1cm$

The base of largest cone that can be cut out from a cube touches all the edges of the base of the cube and its height is same on the edge of the cube.

Diameter of cone $=$ Edge of cube
Radius = $\frac{\text{Edge of a cube}}{2}$
= $\frac{4.2}{2}$
=$2.1cm$