Question

An equilateral triangular pyramid has a slant height of 3.8inches. The triangular base has a perimeter of 4.8inches and an area of 1.1 sq inches. What is the surface area of the pyramid

Answer 1

10.22 inches

Explanation:

From the question we have the necessary information to calculate the surface area of the pyramid.

Surface area of pyramid= A+(1/2×p×s)

Where A = Area of the base of the pyramid

P= Perimeter of the base

S= Slant height of the pyramid

Here the perimeter is 4.8

and the area is 1.1

slant height is 3.8

~ 1.1+(1/2×4.8×3.8)

=9.12 + 1.1

=10.22 inches

Answer 2

Hence surface area = 7.94 sq inches

Explanation:

Formula of surface area of equilateral triangular pyramid = A + (3/2) bh

A = the area of the pyramid's base = 1.1 sq inches

b = the base of one of the faces, = 4.8 ÷ 4 = 1.2 inches

h = slant height of one of the faces = 3.8 inches

Hence surface area = A + (3/2)bh = 1.1 + (3/2)(1.2 x 3.8) = 7.94 sq inches