Arc CD is [tex]\frac{1}{4}[/tex] of the circumference of a circle. What is the radian measure of the central angle?

A. [tex]\frac{\pi}{4}[/tex] radians
B. [tex]\frac{\pi}{2}[/tex] radians
C. [tex]2\pi[/tex] radians
D. [tex]4\pi[/tex] radians



Answer :

To determine the radian measure of the central angle corresponding to arc CD, we need to understand the relationship between the arc length and the central angle.

Given:
- Arc CD is [tex]\(\frac{1}{4}\)[/tex] of the circumference of the circle.

First, recall that the circumference of a circle is given by [tex]\(C = 2\pi r\)[/tex], where [tex]\(r\)[/tex] is the radius. The entire circumference corresponds to a central angle of [tex]\(2\pi\)[/tex] radians.

Since arc CD is [tex]\(\frac{1}{4}\)[/tex] of the circumference, the central angle corresponding to arc CD will be [tex]\(\frac{1}{4}\)[/tex] of [tex]\(2\pi\)[/tex] radians.

To find this angle, we calculate:
[tex]\[ \text{Central angle} = \frac{1}{4} \times 2\pi \][/tex]

By simplifying the product:
[tex]\[ \text{Central angle} = \frac{1}{4} \times 2\pi = \frac{2\pi}{4} = \frac{\pi}{2} \][/tex]

Therefore, the radian measure of the central angle is:

[tex]\[ \boxed{\frac{\pi}{2}} \][/tex]