1/14 Arc Length in Radians

A complete circle includes how many radians?

• $\pi$

• $180\degree$

• $2\pi$

A radian is __.

• a unit of angle, equal to an angle at the center of a circle whose arc is equal in length to the radius.

• a unit of length, equal to an arc measure divided by radius

• a unit of weight, equal to the diameter of the circle whose arc is equal to the circumference of the circle.

Determine the length of the arc.

• $\pi\ cm$

• $\frac{\pi}{2}\ cm$

• $\frac{\pi}{4}\ cm$

Determine the length of the arc.

• $8\pi\ in$

• $4\pi\ in$

• $2\pi\ in$

Determine the length of the arc.

• $\frac{2\pi}{3}\ cm$

• $\frac{\pi}{6}\ cm$

• $\frac{\pi}{4}\ cm$