# WarmUp p 22 Find the lateral area and

• Slides: 22

Warm-Up: p. 22 Find the lateral area and surface area of each prism. 1.

Warm-Up: p. 22 Find the lateral area and surface area of each prism. 2.

5 6 12. 2 Homework Answers: p. 26 (5 – 8) 7 8

Section 12. 3 Notes: Surface Areas of Pyramids and Cones

Vocabulary! Regular Pyramid Lateral Faces Vertex A pyramid that has a base that is a regular polygon and the altitude has an endpoint at the center of the base. Faces that meet at the vertex. In a regular pyramid, they are all congruent isosceles triangles. The point where the lateral faces meet.

Vocabulary! Lateral Edge The intersection of two lateral faces. All the lateral edges are congruent in a regular pyramid. Slant Height The height of each lateral face, ℓ.

Label the Regular Pyramid with the given information.

Vocabulary! Lateral Area of a Regular Pyramid

Example 1: Find the lateral area of the square pyramid to the nearest tenth.

Vocabulary! Surface Area of a Regular Pyramid

Example 2: Find the surface area of the square pyramid to the nearest tenth.

Example 3: Find the surface area of the regular pyramid to the nearest tenth.

You Try! 1. Find the surface area of the square pyramid.

You Try! 2. Find the surface area of the regular pyramid.