Perpendicular & Angle
Bisectors
Lesson 5-2
Learning Goal: Use properties of
perpendicular and angle bisectors
Reviewing vocabulary

What does perpendicular mean?
To intersect at a 90o angle

What does a bisector do to a segment or
angle?
Cuts it into two equal pieces
Think about it…
Where can I place a t-shirt stand so it is
equidistant from the Roller Coaster and
Spaceship?
The distance from a point to a segment
Compare triangle ADC and
Triangle BDC.

If the above is true, how does
AC compare with BC? Why?


Equidistant – a point that is the same
distance from two objects
Example 1: Using the
Perpendicular Bisector Theorem
A) What is AB?
B) What is QR?
Think about it…Answer time!
Example 2: Structure Placement
Where can I place a t-shirt stand so it is
equidistant from the Roller Coaster and
Spaceship? Paddle boats and Spaceship?
Classwork part A
Workbook pg 123-124 #4-7, 14-19
Back to Notes
The distance from a point to a line
is the length of the perpendicular
segment from the point to the line.
Example 3: Using Angle Bisectors Theorem
A) What is RM?
B) What is FB?
Would Perpendicular Bisector
or Angle Bisector be useful?

Which school is
equidistant from the
subway stations at Union
Square and 14th street?

Is St. Vincent’s Hospital
equidistant from Village
Kids Nursery School and
Legacy School?
Would Perpendicular Bisector or
Angle Bisector be useful?
Where should you position yourself so you
have the best chance of stopping the ball,
along the perpendicular bisector to XY or
angle bisector of angle P?
Note the difference…

An angle bisector contains all the points
equidistant from 2 LINES.

A perpendicular bisector contains all of the
points equidistant from 2 POINTS.
Classwork part b
Workbook pg 125 #1-6
Homework: chapter 4 review

Part 1: Triangle congruency worksheet

Part 2 (do on the back of worksheet):
textbook pg 291 #9 – 12 AND
pg 293 #1, 9, 10, 13, 14

We will go over these before the test on
Tuesday.