List as many ways as you can think of for estimating the value of .

Draw a (fairly large) circle on a blank sheet of paper. We’ll think of this as a unit circle.

Divide the unit circle into equal wedges each with its vertex at the center of the circle . On each wedge, call the two corners of the wedge that lie on the circle and . Let denote the area of the triangle and let denote the measure of the angle at . Explain how to estimate the area of the circle with triangle . What is your estimate?
Divide the unit circle into equal wedges each with its vertex at the center of the circle . On each wedge, call the two corners of the wedge that lie on the circle and . Let denote the area of the triangle and let denote the measure of the angle at . Explain how to estimate the area of the circle with triangle . What information do you need to know to actually do this computation?
Given an angle , explain the relation of and to the unit circle. How could these values help with the calculation described above?
Divide the unit circle into equal wedges each with its vertex at the center of the circle . On each wedge, call the two corners of the wedge that lie on the circle and . Let denote the area of the triangle and let denote the measure of the angle at . Explain why someone would be interested in the value of:
Recalling that: Explain why:
Let’s fill out the following table (a calculator will help!): What do you notice?