Exterior Angle Theorem Parallel Lines Cut by a Transversal 5.5 Exterior Angle Theorem Parallel Lines Cut by a Transversal Objectives: To learn and apply the concepts of Exterior Angles and Parallel Lines Cut by a Transversal

Example 1 Find x.

Exterior Angle Theorem The measure of an exterior angle of a triangle is equal to the sum of the measures of the two remote interior angles.

Example 2 Find x.

Transversal Transversal - A line intersecting two or more other lines in the plane

Interior Angles Interior angles

Exterior Angles Exterior angles

Corresponding Angles Corresponding angles same location relative to intersection

Alternate Interior Angles

Alternate Exterior Angles

Consecutive Interior Angles

Example 3 Find angles 1, 2, and 3.

Example 4 Find the measure of each numbered angle in the figure.