Regina’s work to find the surface area of a square pyramid from its net is shown below.


A square pyramid. The square base has side lengths of 9.4 inches. The triangular sides have a height of 11.9 inches.

Surface area of the pyramid = 4 (one-half (9.4) (12.8)) + 9.4 squared = 329 square inches


What error did Regina make?

She should have used One-half (9.4) (11.9) to represent the area of a single triangle.

She should have multiplied all the terms inside the parentheses by 4 when she simplified.

She should have used One-half (4.7) (12.8) to represent the area of a single triangle.

She should have used a different collection of shapes as the net of the pyramid.