1. Classifying Angles
OBJECTIVES:
ï I CAN NAME ANGLES IN FOUR DIFFERENT WAYS.
ï I CAN CLASSIFY ANGLES AS ACUTE, RIGHT, OBTUSE, OR
STRAIGHT.
ï I CAN IDENTIFY VERTICAL AND ADJACENT ANGLES.
ï I CAN FIND MISSING MEASURES OF ANGLES
2. Angles
A shape formed by two rays sharing a common endpoint;
contains two rays and a vertex
ray
ray
vertex
vertexâpoint common to two rays of a
triangle or two sides of a polygon
rayâhas one endpoint and goes infinitely
in one direction
4. How are angles used in real life?
Transportation
Architecture &
Engineering
5. Naming Angles
There are 4 ways to name an angle:
ï Using the vertex
Example: < O
ï Using the number
Example: < 1
ï Using the points with
the vertex in the middle
Example: < MOP or < POM
6. Name that angleâŠ
ï Using the vertex
ï Using the number
ï Using the points with
the vertex in the middle
7. There are 4 basic types of angles:
ïAcute
ïRight
ïObtuse
ïStraight
8. acute Angle
An acute angle measures less than 90° and looks like this:
It measures more than 0 degrees but less than 90 degrees.
0 < acute angle < 90
11. Right Angles
A right angle measures exactly 90° and looks like this:
We draw the square around the right angle so we quickly identify it as a 90° angle. These
angles are the most common in everyday life: the corner of a door, window, table,
piece of paper.
15. obtuse Angle
An obtuse angle measures more than 90° and looks like this:
It measures more than 90 degrees but less than 180 degrees.
90 < obtuse angle < 180
27. Finding the value of a missing measure using what
we know about vertical anglesâŠ
ï” Find the value of x in the figure below.
YOU TRY!_____________________________
ï” What is the value of x in the figure below?
29. Exit slip
Show me what you learned today!
Complete the Exit Slip and turn it in to
tray 1 on your way out when I dismiss you.
DONâT FORGET TO DO YOUR HOMEWORK
& COMPLETE HOMEWORK LOG
