Download Vertical Angles and Angle Bisectors 3-3D - Winterrowd-math

Vertical Angles and Angle
Bisectors 3-3D
What are vertical angles?
What is an angle bisector?
Definition
Two angles are vertical angles if and only if
their sides form two pairs of opposite rays.
OR…When two lines intersect, they form
two pairs of vertical angles.
2
1
3
4
Measuring Time
You will need your protractor and 2 pieces of linguini.
With your partner create vertical angles. Measure all
four angles. What do you find?
Change your vertical angles and measure all four angles
again. What can you conclude?
Try it
Find the measures of 1, 2, 3.
2
1
3
134°
m1  46
m3  46
m2  134
Definition
LM is the angle bisector of NLP if and only if
M is in the interior of NLP and NLM  MLP.
N
M
L
P
Construction: Angle Bisector
Turn to Page 208 and read the
4 steps to construct an angle
bisector.
Get your compass and a sheet
of paper.
Let’s try one together.
Theorems
Vertical angles are congruent.
Two perpendicular lines form four
right angles.
• What are vertical angles?
Vertical angles are formed by two
intersecting lines.
• What is an angle bisector?
A ray that cuts an angle in two.
Assignment 3-3D
Page 209, 1-18, 20-21