Question

PLEASE HELP!

What is the lateral surface area of the triangular pyramid? Use the net of the pyramid to find the lateral surface area.
___in^2

Answer 1

If the lateral surface is just the three side triangles: 39.9 in^2

Answer 2

The lateral area is the area of the three triangular sides in white. Do not include the area of the triangular base in grey.

Looking at the net to the right, you see the base and height of each white triangle.

Back side: base = 6 in.; height = 5.2 in.
Right side: base = 3 in.; height = 5.8 in.
Left side: base = 6 in.; height = 5.2 in.

Area of triangle = bh/2

A(back) = (6 in.)(5.2 in.)/2 = 15.6 in.^2
A(right) = (3 in.)(5.8 in.)/2 = 8.7 in.^2
A(left) = (6 in.)(5.2 in.)/2 = 15.6 in.^2

Lateral area = 15.6 in.^2 + 8.7 in.^2 + 15.6 in.^2 =

Lateral area = 39.9 in.^2