Question

Given that a circle of radius $r$ is broken down into many small sectors and are made to form a rectangle with length $l=\pi r$ and width $w=r$, what is the area of the rectangle?

• A. $a=\frac{\pi r}{2}$
• B. $a=\pi r$
• C. $a=\pi r^2$
• D. $a=\frac{\pi r^2}{2}$

Answer 1

The correct option is C $a=\pi r^2$

area of a rectangle:
$a=l\times w$
$a=\pi r\times r$
$a=\pi r^2$