# Geometry Notes – Lesson 2.5 Name ______________________________________

```Notes – Lesson 2.5
Geometry
Name ______________________________________
Theorem???: _____________________________________________
Vertical Angles Theorem.
_______________________________________________________
(Picture)
__________ and __________
Congruent Supplements Theorem.
________________________________________________________________
________________________________________________________________
Given:
 1 and  2 are supplementary.
 3 and  2 are supplementary.
Proof.
 1 and  2? _______________________________
 3 and  2? ________________________________
So now we can say _____________________ = ________________________ by substitution.
What happens if we subtract
 2 from both sides of the equation,
what are we left with? ___________________________
What conclusion can we make? If two angles are _____________________ of the _______________ angle,
then the two angles are ____________________________.
This is the ________________________________________________ Theorem.
Congruent Complements Theorems:
2.3 ________________________________________________________________
____________________________________________________________________
2.4 ________________________________________________________________
____________________________________________________________________
2.5 ________________________________________________________________
____________________________________________________________________
Find the value of each variable.
1.
2.
4.
5.
3.
```