Question

A section of a rectangle is shaded to form a rhombus. The length of one side of the rectangle is 15, and the height is x.
The shaded figure is a rhombus.

The area of the shaded section is 60 square units. What is the value of x?

4 units
6 units
8 units
9 units

Answer 1

The rhombus is formed by joining the midpoints of the rectangle’s sides, so its diagonals are the rectangle’s length (15) and height (x). The area of a rhombus is half the product of its diagonals:

(15 · x) / 2 = 60
15x = 120
x = 8

Answer: 8 units.