Question

The area of the unshaded region is 22.5cm2 . What is the area of the rectangle?A) 11.25cm2B) 22.5cm2C) 45cm2D) 90cm2

Answer 1

Let's use the variable b to represent the white triangle base (which is the width of the rectangle), and the variable h to represent the white triangle height (which is the length of the rectangle).

The white triangle area is given by:

`A=(b\cdot h)/(2)=22.5\text{ cm}^2`

The area of the rectangle is given by the product of its length and its width, so we have:

`A_2=b\cdot h=2\cdot((b\cdot h)/(2))=2\cdot A=2\cdot22.5=45\text{ cm}^2`

Therefore the correct option is C.