Presentation for teaching the basics of angles and measuring them

1. 1-4
Measuring Angles

2. Angles are what we get when we put two
rays together with the same endpoint.
They are made up of a vertex, the shared
endpoint, and two sides, the rays. We have
ways of measuring, naming, and comparing
angles.

4. When we name an angle, the vertex must
always go in the middle. Once an angle is
drawn, it makes two sections: the interior,
inside of the angle, and the exterior,
outside of the angle.

5. Problem 1: Naming Angles

7. To measure an angle, we use degrees. When we
want to indicate the measure of an angle, we
put m in front of the angle’s name.
A circle has 360 degrees, so one degree is 1/360
of a circle. We often measure angles with a
protractor, and this is related to a new postulate.

9. Just like distance tells us how long a segment is
by subtracting the coordinates of its endpoints,
we can find the measure of an angle by
subtracting the numbers that go with its rays on
a protractor.

10. We can classify angles using their measures.

11. Problem 2: Measuring and Classifying Angles

13. Like congruent segments, if two angles
have the same measure, we say they are
congruent angles. We have special marks
to show angles are congruent.

14. Problem 3: Using Congruent Angles

16. Just like we a postulate for adding
segments, we have one for adding angles.

17. Problem 4: Using the Angle Addition Postulate

19. If what is and ?
4 𝑥−203 𝑥+14
Q
T
S
R
Practice

20. 5 𝑥 −33
4 𝑥+51
Y Z
W
X
Practice

21. Cut in half
R
P
C
A
B
4 𝑥−7
2 𝑥+1
Practice