Question

According to historical records, the Great Pyramid of Giza was originally about 147 meters tall. Assuming it was built with its faces at a 52° incline, which of the following is the original length of one of its sides?a. 91 m.

b. 115 m.
c. 181 m.
d. 230 m.

Answer 1

230

Explanation:

147/tan 52° = 1.28 * 2 = 230 (rounded to nearest meter)

Answer 2

115m

Explanation:

Note that one of the face of a pyramid is a right angled triangle.

Since the pyramid was about 147m tall, the height of triangle will be 147m. If one of the faces is built with one of its faces at 52° to the incline, we can find the original length of one of its sides using SOH CAH TOA

tan(theta) = opposite/adjacent

Given theta = 52°, opposite = 147m (the side directly opposite the angle)

Substituting we have;

Tan52° = 147/adjacent

Adjacent = 147/tan52°

Adjacent = 114.8m

= 115m

Therefore 115m is the original length of one of its side