1. Objective-To find missing angles using rules of geometry.
Supplementary Angles-
Angles whose sum
is 180 . a b

2. Find the value of x. x 30
x = 180
x = 150

3. Find the supplement of the given angle.
1) 40
140
5) 89 91
2) 18
162
6) 23
157
3) 153 27
7) 131 49
4) 65
115
8) 118 62

4. Write a variable equation and solve.
Find an angle whose supplement
is 30 less than twice the angle. x
2x - 30
x + (2x - 30) = 180
3x - 30 = 180
3x = 210 70
x = 70

5. Complementary Angles sum is 90 . b a x+ 40 = 90 - 40 -40 x 40 x = 50
- Angles whose
sum is 90 . b a
x+ 40 = 90 x 40
x = 50

6. Find the complement of... 1) 20 70 2) 47 43 No complement 3) 100
4) the supplement of 150
the complement of the supplement of 150
the complement of 30
= 60

7. Write a variable equation and solve.
Find an angle whose complement is 20
more than three times the angle.
x + 3x + 20 = 90 x
4x + 20 = 90
3x + 20
4x = 70
x = 17.5

8. angles of any triangle is always 180 . b
180 Rule for Triangles
- the sum of the interior
angles of any triangle is
always 180 . b 80 40 x a c
x = 180
x = 180
x = 60

9. Find each angle below.
y + 14 = 63
2y - 10
2y - 10 = 88
y = 29
y+14
y - 20
180
(y + 14) + (2y - 10) + (y - 20) = 180
4y - 16 = 180
4y = 196
y = 49

10. Vertical Angles Theorem
- the opposite angles
of intersecting lines
must be equal.

11. Vertical Angles Theorem
- the opposite angles
of intersecting lines
must be equal.

12. Vertical Angles Theorem
- the opposite angles
of intersecting lines
must be equal.
Find the missing angles a, b and c. 25
155 b c a 25

13. Vertical Angles Theorem
- the opposite angles
of intersecting lines
must be equal.
Find the missing angles a, b and c. 25
155 b c a
155 25

14. Find the missing angle. x 40
132

15. Find the missing angle.
119
124 x