Question

Use the net to find the surface area of the regular pyramid.

A net includes four equilateral triangles. One triangle is shaded and it is a base. Each unshaded triangle shares a side with the shaded triangle. The shaded triangle has a side edge of 10 millimeters and area of base is 43.3 squared millimeters. The height of each unshaded triangle is 9 millimeters.


mm2

Answer 1

Answer: The surface area is 173.2 mm²

Step-by-step explanation: If the four triangles are equilateral and one of the sides is 10 then all the other sides must be 10 as well, meaning that the surface area of each triangle is 43.3 mm². That means that to find the surface area of the whole pyramid you must multiply 43.3 by 4 because there are 4 separate triangles.

43.3 × 4 = 173.2