Question

Martin needs 108 square inches of metal to make a yield sign. If the height of the sign is 12 inches, how long is the top edge of the sign?

A 9 in.
B 18 in.
C 54 in.
D 96 in.

Answer 1

The correct answer is B. 18 inches.

Explanation:

Let's recall that Yield signs are shaped like downward-pointing triangles (as you can see in the picture below) and the formula for finding the Area of a triangle is:

Area = (Base * Height) /2

Replacing with the real values we have:

108 = (Base * 12)/2

216 = 12 * Base

Base = 216/12

Base = 18 inches

The top edge of the sign is 18 inches length.