Concept Check If the radius of a circle is doubled, how is the length of the arc intercepted by a fixed central angle changed?

Find the length to three significant digits of each arc intercepted by a central angle in a circle of radius r. See Example 1. r = 12.3 cm , θ = 2π/3 radians

Find the length to three significant digits of each arc intercepted by a central angle in a circle of radius r. See Example 1. r = 1.38 ft , θ = 5π/6 radians

Find the length to three significant digits of each arc intercepted by a central angle in a circle of radius r. See Example 1. r = 4.82 m , θ = 60°

Find the length to three significant digits of each arc intercepted by a central angle in a circle of radius r. See Example 1. r = 15.1 in. , θ = 210°

Distance between Cities Find the distance in kilometers between each pair of cities, assuming they lie on the same north-south line. Assume the radius of Earth is 6400 km. See Example 2. Panama City, Panama, 9° N, and Pittsburgh, Pennsylvania, 40° N

Distance between Cities Find the distance in kilometers between each pair of cities, assuming they lie on the same north-south line. Assume the radius of Earth is 6400 km. See Example 2. Farmersville, California, 36° N, and Penticton, British Columbia, 49° N

Distance between Cities Find the distance in kilometers between each pair of cities, assuming they lie on the same north-south line. Assume the radius of Earth is 6400 km. See Example 2. New York City, New York, 41° N, and Lima, Peru, 12° S

Distance between Cities Find the distance in kilometers between each pair of cities, assuming they lie on the same north-south line. Assume the radius of Earth is 6400 km. See Example 2. Halifax, Nova Scotia , 45° N, and Buenos Aires, Argentina, 34° S