Key Concepts: Surface Areas of Pyramids and Cones

Lateral Area of a Regular Pyramid

L = ½Pℓ

where P is the perimeter of the base and ℓ is the slant height.

Surface Area of a Regular Pyramid

S = ½Pℓ + B

Lateral Area of a Cone

L = πrℓ

Surface Area of a Cone

S = πrℓ + πr²

Note

The slant height ℓ, height h, and radius r are related by: ℓ² = h² + r².