Question

The radius of a circle is 9 feet. What is the length of a 90° arc?

Answer 1

Answer:

$\frac{9\pi }{2}$ feet, or 14.14 feet

Step-by-step explanation:

Use the arc length formula:

s = rθ

To use the formula, we have to convert the central angle to radians.

90° is equivalent to $\frac{\pi }{2}$ radians, so plug this and the radius into the formula:

s = rθ

s = (9)($\frac{\pi }{2}$)

s = $\frac{9\pi }{2}$

So, the length of the arc is $\frac{9\pi }{2}$ feet, or approximately 14.14 feet