1. Measuring Angles

How many radians is $150°$?

Convert each degree measure to radians. Leave answers as multiples of π. See Examples 1(a) and 1(b). 30°

How many radians is $-135°$?

Convert each degree measure to radians. Leave answers as multiples of π. See Examples 1(a) and 1(b). 90°

In Exercises 7–12, find the radian measure of the central angle of a circle of radius r that intercepts an arc of length s. Radius, r: 6 yards Arc Length, s: 8 yards

In Exercises 71–74, find the length of the arc on a circle of radius r intercepted by a central angle θ. Express arc length in terms of 𝜋. Then round your answer to two decimal places. Radius, r: 12 inches Central Angle, θ: θ = 45°

In Exercises 1–6, the measure of an angle is given. Classify the angle as acute, right, obtuse, or straight. 𝜋

Work each problem. See Example 5. Angle Measure Find the measure (in radians) of a central angle of a sector of area 16 in² a circle of radius 3.0 in.

CONCEPT PREVIEW Find the measure of each central angle (in radians).

Convert each degree measure to radians. Leave answers as multiples of π. See Examples 1(a) and 1(b). 3600°

Work each problem. See Example 5. Arc Length A circular sector has an area of 50 in² . The radius of the circle is 5 in. What is the arc length of the sector?

Convert 135° to an exact radian measure.

In Exercises 5–7, convert each angle in radians to degrees. 5𝜋 3

Find the length of the arc on a circle of radius 20 feet intercepted by a 75° central angle. Express arc length in terms of 𝜋. Then round your answer to two decimal places.