Section 5.1 Worksheet 1.) The measure of an exterior angle of a triangle is equal to the sum of the measures of the two interior angles. For #2-5, classify the triangle by its sides and by its angle measures. 2.) X 3.) M N 5.) 4.) J For #6 and #7, classify AABC by its sides. Then determine whether it is a right triangle? 6.) A(2,3), B(6,3), C(2,7) 7.) A(3,3), B(6,9), C(6,-3) Classify by sides: Is it a right triangle? For #8-11, find m21. Then classify the triangle by its angles. 8.) 78 31 Classify by sides: Is it a right triangle? mz1 = Classify by its angles: B