Vocabulary

Surface area – the sum of the areas of all of the surfaces of a three-dimensional figure.

Regular pyramid – a pyramid with a base that is a regular polygon.

Lateral surface area – the sum of all of the lateral faces.

Slant height – the height of a lateral face.

Concepts

Finding the perimeter of the base of a pyramid.

Rules

1. Determine whether the base is a square or a rectangle.
2. If the base is a square, then the perimeter is 4 times the length of one side.
3. If the base is an equilateral triangle, then the perimeter is 3 times the length of one side.

Example

What is the perimeter of the base of this pyramid?

Solution

The base is a square measuring 10 km along each side. The perimeter is found by taking the sum of the four sides of the square or by using the formula P = 4s. The perimeter is 40 km. 

Pre-requisite Skills

Measurement - Perimeter (4.13.7)