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The Exterior angle Theorem Date Name .
The Exterior Angle Theorem
An exterior angle of a triangle is an angle outside the triangle that forms a linear pair with one of the angles of the
triangle. The opposite interior angles (remote interior angles) of an exterior angle are the two nonadjacent interior angles
of a triangle. The measure of an exterior angle of a triangle is equal to the sum of the measures of the two opposite
interior angles.
Example: x is an exterior angle at T.
1 and 2 are the opposite interior angles of x.
Therefore, mx = m1 + m2.
Examples: Apply the exterior angle theorem to solve each exercises below.
Exercises: Apply the exterior angle theorem to solve each exercises below.
