Question

In a circle, a central angle whose measure is pi/2 radians intercepts an arc whose length is 3pi/2 centimeters. How many centimeters are in the radius of the circle?

Answer 1

$\frac{3\pi}{2}$ cm = quarter of circumference

$=\frac{2r\pi}{4} \\ \\=\frac{r\pi}{2} \\ \\ \Rightarrow r=3 \text{ cm}$