1. 3-4: Angles of a Triangle

4. A triangle is the figure formed by 3 segments joining 3 noncollinear points. The points are called vertices (plural of vertex), and the segments are called sides.

7. Cor. 1: If two angles of one triangle are congruent to two angles of another triangle, then the third angles are congruent. Cor. 2: Each angle of an equiangular triangle is 60. Cor. 3: In a triangle, there can be at most one right or obtuse angle. Cor. 4: The acute angles of a right triangle are complementary.

10. The measure of an exterior angle of a triangle is equal to the sum of the measures of the two remote interior angles. Ex) Draw all exterior angles, and find their measures

12. p. 97; #1-25 odd, 12, 14 (Hint for #25: Look at the two overlapping triangles, and use Corollary 1) Quiz tomorrow!