Degrees Radians Arc Length

How many radians are in one full rotation around a circle?

•   360 degrees

• ^{2 radians}

How do you find the perimeter around a circle (length)?

A wheel spins in place in a counterclockwise direction. The radius of the wheel is 6 inches. If a point has rotated 1/4 of a rotation, how far has the point traveled? (Do not erase your board after this problem)

• 2π radian

A wheel spins in place in a counterclockwise direction. The radius of the wheel is 6 inches. If a point has rotated 1/4 of a rotation, what angle has the point traveled? (Erase after)

A wheel spins in place in a counterclockwise direction. The radius of the wheel is 3 yards. If a point has rotated 2/3 of a rotation, how far has the point traveled? (Don't erase)

A wheel spins in place in a counterclockwise direction. The radius of the wheel is 3 yards. If a point has rotated 2/3 of a rotation, what angle has the point traveled? (Erase after)

A wheel spins in place in a counterclockwise direction. The radius of the wheel is 1 cm. If a point has rotated 3 rotations, how far has the point traveled? (Don't erase)

A wheel spins in place in a counterclockwise direction. The radius of the wheel is 1 cm. If a point has rotated 3 rotations, what angle has the point traveled? (Erase)

On a unit circle, the arc length (distance traveled) and radian measure will be the same because the radius is ___