1. Complimentary & Supplementary Angles
Angles in Geometry can be added and subtracted.

2. Complimentary & Supplementary Angles
Angles in Geometry can be added and subtracted.
For example, if I have a 40° angle and add it to a 10° angle I get a total of 50°.

3. Complimentary & Supplementary Angles
Angles in Geometry can be added and subtracted.
For example, if I have a 40° angle and add it to a 10° angle I get a total of 50°.
EXAMPLE #1 : Add the two given angles
37°
25°

4. Complimentary & Supplementary Angles
Angles in Geometry can be added and subtracted.
For example, if I have a 40° angle and add it to a 10° angle I get a total of 50°.
EXAMPLE #1 : Add the two given angles
Solution : 37° + 25° = 62°
37°
25°

5. Complimentary & Supplementary Angles
In the diagram, ∠𝐴𝐵𝐶=55°, and ∠𝐴𝐵𝐷=115°, find the measure of ∠𝐶𝐵𝐷. A C B D

6. Complimentary & Supplementary Angles
In the diagram, ∠𝐴𝐵𝐶=55°, and ∠𝐴𝐵𝐷=115°, find the measure of ∠𝐶𝐵𝐷.
SOLUTION : ∠𝐴𝐵𝐷=∠𝐴𝐵𝐶+∠𝐶𝐵𝐷
115°=55°+∠𝐶𝐵𝐷 A C
115°
55° ? B D

7. Complimentary & Supplementary Angles
In the diagram, ∠𝐴𝐵𝐶=55°, and ∠𝐴𝐵𝐷=115°, find the measure of ∠𝐶𝐵𝐷.
SOLUTION : ∠𝐴𝐵𝐷=∠𝐴𝐵𝐶+∠𝐶𝐵𝐷
115°=55°+∠𝐶𝐵𝐷
115° −55°=∠𝐶𝐵𝐷 A C
115°
55° ? B D

8. Complimentary & Supplementary Angles
In the diagram, ∠𝐴𝐵𝐶=55°, and ∠𝐴𝐵𝐷=115°, find the measure of ∠𝐶𝐵𝐷.
SOLUTION : ∠𝐴𝐵𝐷=∠𝐴𝐵𝐶+∠𝐶𝐵𝐷
115°=55°+∠𝐶𝐵𝐷
115° −55°=∠𝐶𝐵𝐷
∠𝐶𝐵𝐷=60° A C
115°
55°
60° B D

9. Complimentary & Supplementary Angles
Complimentary angles add up to 90°.

10. Complimentary & Supplementary Angles
Complimentary angles add up to 90°.
So given a 30° angle, its complimentary angle would be 60°. ( 90° −30°=60° )

11. Complimentary & Supplementary Angles
Complimentary angles add up to 90°.
So given a 30° angle, its complimentary angle would be 60°. ( 90° −30°=60° )
Supplementary angles add up to 180°.

12. Complimentary & Supplementary Angles
Complimentary angles add up to 90°.
So given a 30° angle, its complimentary angle would be 60°. ( 90° −30°=60° )
Supplementary angles add up to 180°.
So given a 140° angle, its supplementary angle would be 40°. ( 180° −140°=40° )

13. Complimentary & Supplementary Angles
Complimentary angles add up to 90°.
So given a 30° angle, its complimentary angle would be 60°. ( 90° −30°=60° )
Supplementary angles add up to 180°.
So given a 140° angle, its supplementary angle would be 40°. ( 180° −140°=40° )
** An easy way to remember these is “c” comes before “s” in the alphabet and 90 comes before 180 on the number line…

14. Complimentary & Supplementary Angles
Let’s set up a chart and practice calculating complimentary and supplementary angles.

15. Complimentary & Supplementary Angles
Let’s set up a chart and practice calculating complimentary and supplementary angles.
Calculate the complimentary angle for each given angle.
Given Angle
Complimentary Angle
15°
56°
45°
27°
61°

16. Complimentary & Supplementary Angles
Let’s set up a chart and practice calculating complimentary and supplementary angles.
Calculate the complimentary angle for each given angle.
Given Angle
Complimentary Angle
15°
90°−15°=75°
56°
45°
27°
61°

17. Complimentary & Supplementary Angles
Let’s set up a chart and practice calculating complimentary and supplementary angles.
Calculate the complimentary angle for each given angle.
Given Angle
Complimentary Angle
15°
90°−15°=75°
56°
90°−56°=34°
45°
27°
61°

18. Complimentary & Supplementary Angles
Let’s set up a chart and practice calculating complimentary and supplementary angles.
Calculate the complimentary angle for each given angle.
Given Angle
Complimentary Angle
15°
90°−15°=75°
56°
90°−56°=34°
45°
90°−45°=45°
27°
61°

19. Complimentary & Supplementary Angles
Let’s set up a chart and practice calculating complimentary and supplementary angles.
Calculate the complimentary angle for each given angle.
Given Angle
Complimentary Angle
15°
90°−15°=75°
56°
90°−56°=34°
45°
90°−45°=45°
27°
90°−27°=63°
61°

20. Complimentary & Supplementary Angles
Let’s set up a chart and practice calculating complimentary and supplementary angles.
Calculate the complimentary angle for each given angle.
Given Angle
Complimentary Angle
15°
90°−15°=75°
56°
90°−56°=34°
45°
90°−45°=45°
27°
90°−27°=63°
61°
90°−61°=29°

21. Complimentary & Supplementary Angles
Let’s set up a chart and practice calculating complimentary and supplementary angles.
Calculate the complimentary angle for each given angle.
Calculate the supplementary angle for each given angle.
Given Angle
Complimentary Angle
15°
90°−15°=75°
56°
90°−56°=34°
45°
90°−45°=45°
27°
90°−27°=63°
61°
90°−61°=29°
Given Angle
Supplementary Angle
119°
78°
135°
18°
99°

22. Complimentary & Supplementary Angles
Let’s set up a chart and practice calculating complimentary and supplementary angles.
Calculate the complimentary angle for each given angle.
Calculate the supplementary angle for each given angle.
Given Angle
Complimentary Angle
15°
90°−15°=75°
56°
90°−56°=34°
45°
90°−45°=45°
27°
90°−27°=63°
61°
90°−61°=29°
Given Angle
Supplementary Angle
119°
180°−119°=61°
78°
135°
18°
99°

23. Complimentary & Supplementary Angles
Let’s set up a chart and practice calculating complimentary and supplementary angles.
Calculate the complimentary angle for each given angle.
Calculate the supplementary angle for each given angle.
Given Angle
Complimentary Angle
15°
90°−15°=75°
56°
90°−56°=34°
45°
90°−45°=45°
27°
90°−27°=63°
61°
90°−61°=29°
Given Angle
Supplementary Angle
119°
180°−119°=61°
78°
180°−78°=102°
135°
18°
99°

24. Complimentary & Supplementary Angles
Let’s set up a chart and practice calculating complimentary and supplementary angles.
Calculate the complimentary angle for each given angle.
Calculate the supplementary angle for each given angle.
Given Angle
Complimentary Angle
15°
90°−15°=75°
56°
90°−56°=34°
45°
90°−45°=45°
27°
90°−27°=63°
61°
90°−61°=29°
Given Angle
Supplementary Angle
119°
180°−119°=61°
78°
180°−78°=102°
135°
180°−135°=45°
18°
99°

25. Complimentary & Supplementary Angles
Let’s set up a chart and practice calculating complimentary and supplementary angles.
Calculate the complimentary angle for each given angle.
Calculate the supplementary angle for each given angle.
Given Angle
Complimentary Angle
15°
90°−15°=75°
56°
90°−56°=34°
45°
90°−45°=45°
27°
90°−27°=63°
61°
90°−61°=29°
Given Angle
Supplementary Angle
119°
180°−119°=61°
78°
180°−78°=102°
135°
180°−135°=45°
18°
180°−18°=162°
99°

26. Complimentary & Supplementary Angles
Let’s set up a chart and practice calculating complimentary and supplementary angles.
Calculate the complimentary angle for each given angle.
Calculate the supplementary angle for each given angle.
Given Angle
Complimentary Angle
15°
90°−15°=75°
56°
90°−56°=34°
45°
90°−45°=45°
27°
90°−27°=63°
61°
90°−61°=29°
Given Angle
Supplementary Angle
119°
180°−119°=61°
78°
180°−78°=102°
135°
180°−135°=45°
18°
180°−18°=162°
99°
180°−99°=81°