Name __________________________________ Date ___________________ LESSON 1.5 Practice C 1 and 2 are complementary angles and 2 and 3 are supplementary angles. Given the measure of 1, find m2 and m3. 1. ml = 43 2. ml = 28° 3. ml = 69.5° 4. ml = 17.5° Find mABC and mCBD. 5. 6. 7. In Exercises 8–15, use the diagram. Tell whether the angles are vertical angles, a linear pair, or neither. 1 and 2 l and 3 2 and 4 4 and 5 6 and 8 8 and 9 7 and 10 10 and 11 The measure of one angle is 7 times the measure of its complement. Find the measure of each angle. 17. Two angles form a linear pair. The measure of one angle is 15 times the measure of the other angle. Find the measure of each angle. 18. The measure of one angle is 47 less than the measure of its supplement. Find the measure of each angle. 8. 9. 10. 11. 12. 13. 14. 15. 16. Find the values of x and y. 19. 20. 21. 22. Name _____________________________________ Date ___________________ LESSON 1.5 Practice C continued Tell whether the statement is always, sometimes, or never true. Explain your reasoning. 25. Two vertical angles are adjacent. 26. Two supplementary angles consist of one acute angle and one obtuse angle. 27. An angle that has a complement also has a supplement. A and B are complementary angles. Find mA and mB. 28. mA = 5x mB = (17x + 2) 29. mA = (16x 13) mB = (2x 5) 30. mA = (4x + 31) mB = (2x + 44) 31. mA = (21x + 12)° mB = (35x 6) A and B are supplementary angles. Find mA and mB. 32. mA = (x 11) mB = (x 15) 33. mA = (9x 12) mB = (24x 60) 34. mA = (3x 90) mB = (5x 150) 35. mA = (9x 28.5) mB = (5x 101.5) Tell whether the two angles shown are complementary, supplementary, or neither. 36. 37. 38. In Exercises 39–42, use the star at the right and the angles identified to name two pairs of the indicated type of angle pair. 39. Supplementary angles 40. Vertical angles 41. Linear pair 42. Adjacent angles Use the star above. Determine the total number of pairs of vertical angles. Determine the total number of linear pairs (supplementary angles). Determine the total number of pairs of adjacent angles. Answer Key Lesson 1.5 Practice Level C 1. m2 = 47, m3 = 133 2. m2 = 62, m3 = 118 3. m2 = 20.5, m3 = 159.5 4. m2 = 72.5, m3 = 107.5 5. mABC = 64, mCBD = 26 6. mABC = 97, mCBD = 83 7. mABC = 112.5, mCBD = 67.5 8. linear pair 9. vertical angles 10. neither 11. neither 12. vertical angles 13. linear pair 14. neither 15. linear pair 16. 11.25 and 78.75 17. 11.25 and 168.75 18. 66.5 and 113.5 19. x = 5, y = 6 20. x = 6, y = 11 21. x = 7.5, y = 8.5 22. x = 9.5, y = 3.5 23. x = 4, y = 17 24. x = 13.5, y = 3.5 25. Never; Vertical angles do not share a common side. 26. Sometimes; This is true except when both angles are right angles. 27. Always; An angle that has a complement must have a measure less than 90, so there will always be another angle that would make the sum of the two angle measures equal 180. 28. mA = 20, mB = 70 29. mA = 83, mB = 7 30. mA = 61, mB = 29 31. mA = 43.5, mB = 46.5 32. mA = 103, mB = 77 33. mA = 24, mB = 156 34. mA = 67.5, mB = 112.5 35. mA = 141, mB = 39 36. supplementary 37. supplementary 38. complementary 39. Sample answer: 3 and 4, 7 and 10 40. Sample answer: 2 and 4, 3 and 5 41. Sample answer: 2 and 3, 4 and 5 42. Sample answer: 7 an d 8, 9 and 10 43. 10; 20; 20