1. Mr. Schaab’s Geometry Class Our Lady of Providence Jr.-Sr. High School 2014-2015

2.  A triangle is a polygon with three sides.  A triangle with vertices (corners) A, B, and C is called “triangle ABC” or “ △ ABC.”

4.  A triangle’s interior angles are the three angles contained within the boundaries of the triangle.  The exterior angles of a triangle are the angles formed when the sides of the triangle are extended. They always lie outside the triangle.

5.  The sum of the measures of the interior angles of a triangle is 180°.

6.  The measure of an exterior angle of a triangle is equal to the sum of the measures of the two nonadjacent interior angles.

7.  Congruent Figures – If two geometric figures are congruent, then all the parts of one figure are congruent to the corresponding parts of the other figure.  In the diagram, ∠ P and ∠ L are corresponding angles, and JK and QR are corresponding sides.

8.  If two angles of one triangle are congruent to two angles of another triangle, then the third angles are also congruent.  In the diagram, the unlabeled angles must be congruent. What is the measure of both unlabeled angles?  73°