1. Pairs of Angles Find the measure of the supplement of  IGJ. LESSON 7-1 x° + m IGJ = 180° The sum of the measures of supplementary angles is 180º. x° + 145° – 145° = 180° – 145° Subtract 145º from each side. x° = 35°Simplify. The measure of the supplement of m IGJ is 35º. Additional Examples Substitute 145º for m DEF.x° + 145° = 180°

2. The adjacent angles are HGK and KGJ; KGJ and JGI; JGI and IGH; IGH and HGK. The vertical angles are JGI and HGK; HGI and KGJ. Pairs of Angles LESSON 7-1 Name a pair of adjacent angles and a pair of vertical angles in the figure. Find m HGK. Since vertical angles are congruent, m HGK = m JGI = 145°. Additional Examples

3. Pairs of Angles In this figure, if m DKH = 73°, find the measures of GKJ and JKF. LESSON 7-1 m DKE + 90°= 180° DKE and FKE are supplementary. m DKE= 90°Subtract 90º from each side. Additional Examples

4. Pairs of Angles (continued) LESSON 7-1 m KHE + 73° = 90° KHE and DKH are complementary. m KHE = 17°Subtract 73º from each side. GKJ and KHE are vertical angles. m GKJ = m KHE = 17° JKF and DKH are vertical angles. m JKF = m DKH = 73° So, the measure of GKJ is 17° is and the measure of JKF is 73°. Additional Examples