Instead of degrees, angles can be described by a different unit of measure, called a Radian. A "Radian" is the measure of a central angle subtended by an arc with the same length as the radius of the circle. A full circle measures 360 degrees, or 2π radians.
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Goal 2: "I can identify coterminal angles." (OPTIONAL)
Goal 3: "I can identify reference angles." (OPTIONAL)