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 m2 and m3.
1. ml = 43
2. ml = 28°
3. ml = 69.5°
4. ml = 17.5°
Find mABC and mCBD.
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 mA and mB.
28. mA = 5x
mB = (17x + 2)
29. mA = (16x  13)
mB = (2x  5)
30. mA = (4x + 31)
mB = (2x + 44)
31. mA = (21x + 12)°
mB = (35x  6)
A and B are supplementary angles. Find mA and mB.
32. mA = (x  11)
mB = (x  15)
33. mA = (9x  12)
mB = (24x  60)
34. mA = (3x  90)
mB = (5x  150)
35. mA = (9x  28.5)
mB = (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. m2 = 47, m3 = 133
2. m2 = 62, m3 = 118
3. m2 = 20.5, m3 = 159.5
4. m2 = 72.5, m3 = 107.5
5. mABC = 64, mCBD = 26
6. mABC = 97, mCBD = 83
7. mABC = 112.5, mCBD = 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. mA = 20, mB = 70
29. mA = 83, mB = 7
30. mA = 61, mB = 29
31. mA = 43.5, mB = 46.5
32. mA = 103, mB = 77
33. mA = 24, mB = 156
34. mA = 67.5, mB = 112.5
35. mA = 141, mB = 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