Question

In the rectangular pyramid below, l = 16 inches, w = 12 inches, and h = 15 inches

What is the length of s?
A. 22 inches
B. 19 inches
C. 17 inches
D. 13 inches

Answer 1

C. 17 in

Explanation:

s is the slant height

Using the right angle triangle with base L/2 and height h, find s

L/2 = 16/2 = 8

8² + 15² = s²

s² = 289

s = 17

Answer 2

C. 17 inches

Explanation:

We can use the Pythagorean theorem to find the length of s

a^2 +b^2 = c^2

where a is 1/2 l

a = 1/2 (16) = 8

b = h = 15

c =s

8^2 + 15^2 = s^2

64 +225 = s^2

289 = s^2

Take the square root of each side

sqrt(289) = sqrt(s^2)

17 = s