1. Angle Relationships

2. What are Supplementary Angles?
Two angles whose measure add to 180°
Can two acute angles be supplementary?
NO – they will never add to 180° because acute angles are less than 90° each

3. Name a pair of Supplementary Angles
<1 and <2, <3 and <4 <5 and <6, <7 and <8 <2 and <3, <4 and <1 <6 and <7, <8 and <5
Name a pair of Supplementary Angles

4. What are Vertical Angles?
Angles that are formed by intersecting lines
Angles that share a vertex but not a side (E)
Angles that are opposite each other
Vertical angles are CONGRUENT

5. <1 and <3 <6 and <8 <2 and <4 <5 and <7
Name a pair of vertical angles

6. How do we know vertical angles are congruent?

7. By applying the definition of Supplementary angles!!!
An angle and its adjacent supplementary angle will add to 180°

8. A Transversal – a line that cuts two lines at different points

9. What is a corresponding angle?
An angle that is has the same position in a new location Example: <A is in the top right <E is in the top right

10. Name a pair of corresponding angles?
<1 and <5 <2 and <6 <3 and <7 <4 and <8

11. TRUE ! If the two lines cut by a transversal are parallel then the corresponding angles are congruent?
True or False?
m< 1 = m<5

12. What is an alternate interior angle?
An angle that is between the parallel lines on opposite sides of the transversal
Example:
<D is in the inside top left
<E is the inside bottom right

13. <4 and <6 <3 and <5
Name a pair of Alternate Interior Angles

14. What is an alternate exterior angle?
An angle that is above or below the parallel lines on opposite sides of the transversal
Example:
<B is in the outside top left
<G is in the outside bottom right

15. <1 and <7 <2 and <8
Name a pair of Alternate Exterior Angles

16. <1 and <8 <2 and <7 <4 and <5 <3 and <6
Name a pair of non-linear Supplementary Angles

17. Exterior Angles of a Triangle
Is formed by extending the line at the base of the adjacent angle.

18. Finding the measure of an exterior angle of a triangle
The measure of an exterior angle is the sum of the measure of the two opposite (remote) interior angles
<y = <a + <B

19. Finding the measure of an exterior angle of a triangle
Exterior = Interior + Interior
70 = 30 40 70

20. Let’s try a few 1 2 35 40 x 45 x 40 3 4 x 80
120 x 60
140

21. Name a pair of …………