What is the measure of the indicated central angle?

You know that there can be different units of measurement to measure the same thing. For example, length can be measured in feet and meters and temperature can be measured in degrees Celsius and degrees Fahrenheit. We often use formulas to convert between different units of measurement.

There are also two ways to measure angles. You know how to measure them in degrees. Now you will learn how to measure them in radians and how to convert between these two measurements. While degree measure is used in everyday activities such as building construction and surveying land, radian measure is used for many calculations, such as the speed and distance traveled by satellites above the Earth’s surface-including the International Space Station! It is important to be able to measure angles in radians as well as in degrees and to be able to convert between the two systems.