Question

a circle has a circumference of 20. it has an arc of length 4. what is the central angle of the arc, in degrees?

Explanation:

Step1: Find the fraction of the arc length to the circumference.

The circumference of the circle is 20, and the arc length is 4. So the fraction is $\frac{4}{20}=\frac{1}{5}$.

Step2: Multiply the fraction by 360° (the total degrees in a circle).

To find the central angle, we multiply the fraction by 360°: $\frac{1}{5} \times 360^{\circ}=72^{\circ}$.

Answer:

72