Question

Find the surface area of the equilateral triangular pyramid.

A) 97.5 in2 B) 225 in2 C) 322.5 in2 D) 645 in2

Answer 1

The area of the base is given by:
A1 = (1/2) * (15) * (13)
A1 = 97.5
The area of the lateral faces is given by:
A2 = (1/2) * (15) * (10)
A2 = 75
Then, the total surface area is:
A = A1 + 3A2
Substituting values:
A = 97.5 + 3 * (75)
A = 322.5
Answer:
The surface area of the equilateral triangular pyramid is:
C) 322.5 in2