Frustum of a right circular cone is that portion of right circular cone included between the base and a section parallel to the base not passing through the vertex.

Properties of Frustum of Right Circular Cone

• The altitude of a frustum of a right circular cone is the perpendicular distance between the two bases. It is denoted by h.
• All elements of a frustum of a right circular cone are similar to a cone. Here, slant height is denoted by L.

The formula of Frustum of a Right Circular Cone CSA = πL(R + r) TSA = πL(R + r) + πR2+ πr2 V0lume, V = $\begin{array}{l}\frac{\pi h}{3}(R^2+Rr+r^2)\end{array}$

Solved Example

Question: Find the volume of a frustum of a right circular cone with height 20, lower base radius 34 and top radius 19.

Solution:

Given,
h = 20
R = 34
r = 19

V =

V =

V = 14420 π cubic units