\[A_L = \pi (R + r)l\]
Variables
ALlateral surface area (m²)
Rradius of the larger base (m)
rradius of the smaller base (m)
lslant height of the frustum (m)
Description
What is this formula?
This formula calculates the lateral surface area of a frustum of a cone. It represents only the curved side surface, excluding both circular bases.
When to use it
Use this formula when calculating the curved surface area of truncated conical objects.
Example
If a frustum has:
R = 6 m
r = 3 m
l = 5 m
A_L = π(6 + 3) × 5
A_L = 45π
A_L ≈ 141.37 m²
Applications
- Geometry and mathematics
- Engineering design
- Manufacturing
- Sheet metal development
- Industrial modeling