Question

The surface area of the square pyramid shown is 84 square inches. What is the value of $x$ ? Square pyramid with base edge of 6 inches, and a slant height labeled x inches, on a triangular face.

Answer 1

4 inches

Explanation:

The surface area, A of a right square pyramid is given by :

A = a² + 2as

Where, s = height of each triangular surface = x

a = base edge of pyramid

Substituting values into the equation :

A = 84 in² ; a = 6 in ; Slant height, s = x

84 = 6² + 2(6 * x)

84 = 36 + 2(6x)

84 = 36 + 12x

84 - 36 = 12x

48 = 12x

48/12 = 12x / 12

4 = x

Hence, Slant height, x = 4 inches

Answer 2

4 inches

Explanation:

The surface area, A of a right square pyramid is given by :

A = a² + 2as

Where, s = height of each triangular surface = x

a = base edge of pyramid

Substituting values into the equation :

A = 84 in² ; a = 6 in ; Slant height, s = x

84 = 6² + 2(6 * x)

84 = 36 + 2(6x)

84 = 36 + 12x

84 - 36 = 12x

48 = 12x

48/12 = 12x / 12

4 = x

Hence, Slant height, x = 4 inches