Surface Areas of Pyramids Unit 5, Lesson 4

Pyramids Pyramid Pyramid – A three dimensional figure in which one face, the base, is any polygon and the lateral faces are triangles that meet at a common vertex. vertex

Pyramids cont. The altitude of a pyramid is the perpendicular segment from the vertex to the plane of the base. The length of the altitude is called the height. Height Pyramid

Pyramids cont. Regular Pyramid – a pyramid whose base is a regular polygon. Slant Height – the length of the altitude of the lateral face. Slant Height Pyramid

Formulas Lateral Area and Surface Area of a Regular Pyramid Lateral Area Base Perimeter Slant Height Surface Area Lateral Area Base Area B

Example 1: Finding Surface Area of a Pyramid Find the surface area of a square pyramid with base edges 5 m and slant height 3 m.

#2 Finding Surface Area of a Pyramid Find the surface area of a regular hexagonal pyramid with a slant height 20 in and sides 8 in.

#3 Find the surface area of: 12 m

#4 Find the surface area of: 10” 15” 10” S = L + B S = ½ (40)(15) + (10)(10) S = 400 in 2

Pyramids and Prisms

Pyramids and Cylinders