[G.C.5] Circles #5

Objective

Common Core Text:

• • [G.C.5] Derive using similarity the fact that the length of the arc intercepted by an angle is proportional to the radius, and define the radian measure of the angle as the constant of proportionality; derive the formula for the area of a sector.

Said Differently:

• Show why the length of an arc is proportional to the radius

• define the radian measure of the angle as the constant of proportionality

• derive the formula for the area of a sector.

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Explanation

Length of an Arc

Radians

Area of a Sector