Question

Julia made a model of a square pyramid. She used cardboard to construct the model with the dimensions shown. It has an open bottom.

A square pyramid has a square base with side lengths of 8 centimeters, and 4 triangular sides with a height of 5 centimeters.

What is the surface area of the model?
A. 80 cm2
B. 144 cm2
C. 224 cm2
D. 320 cm2

Answer 1

80 cm²

Explanation:

I did it and I got it right

Answer 2

A. 80 cm²

Explanation:

If a square pyramid has an open base, then the surface area is made up of the 4 congruent triangular sides only.

Area of a triangle = 1/2 × base × height

Given:

• Base = 8 cm
• Height = 5 cm

⇒ Area of one triangular face = 1/2 × 8 × 5

= 20 cm²

⇒ Total surface area = 4 triangular faces

= 4 × 20

= 80 cm²