1. BELLRINGER

2. BELLRINGER Write this on the back on your foldable
Congruent segments are segments that have the same length. In the diagram, PQ = RS. Tick marks are used in a figure to show segments of equal length.

3. Midpoint

4. Segment Bisector

5. What is an angle?

6. Bellringer
Have your foldable and homework out on your desk!

7. Angles An angle is a figure formed by two rays with the same endpoint.
pg. 790
An angle is a figure formed by two rays with the same endpoint.
The common endpoint is called the vertex of the angle. The rays are the sides of the angle.
vertex

8. Naming Angles A C B D H F
Ask a student to pick an angle and tell another student which one she is thinking of. I G E

9. Naming Angles A C B D H F
Ask a student to pick an angle and tell another student which one she is thinking of. I G E

10. Naming Angles A C B D H F
Ask a student to pick an angle and tell another student which one she is thinking of. I G E

11. Give Four Ways to Name this Angle
pg. 790
Give Four Ways to Name this Angle J 1 K
If you can give me four ways to name this angle, we’re doing good. L

12. Write the different ways you can name the angles in the diagram.
RTQ, STR,
1, 2

13. pg. 791

14. Angle

15. On back of foldable!
Congruent angles are angles that have the same measure. In the diagram, mABC = mDEF. Arc marks are used to show that the two angles have equal measures.

16. ABC refers to the angle mABC refers to the measurement of the angle
A Distinction!
ABC refers to the angle mABC refers to the measurement of the angle

17. Angle Bisector

18. Measuring Angles
pg. 791
The measure of an angle is usually given in degrees. Since there are 360° in a circle, one degree is 1/360 of a circle.
We can use protractors to measure angles.

19. Let’s play with protractors!
Construct a 50 degree angle.
Construct a 35 degree angle that faces up like a v.
Construct a 120 degree angle.

20. Postulate

21. What is AC?
What is DF?
If three points are collinear, then the lengths of the two shorter segments equals the length of the larger segment. 12 4 A B C E 7 13 D F

22. Segment Addition Postulate
pg. 777
Let A, B, and C be collinear points. If B is between A and C, then AB + BC = AC
Notice: this means the length of segment AB plus the length of segment BC equals the length of segment AC A B C

23. G is between F and H, FG = 6, and FH = 11. Find GH.
FH = FG + GH
11 = 6 + GH
– 6 –6
5 = GH F G H

24. E is between D and F. Find DF.
x = 4
DF = 24

25. S is the midpoint of RT.
Find RS, ST, and RT. R S T
–2x
–3x – 2
RS = 4
ST = 4
RT = 8

26. Angle Addition Postulate
pg. 792
If S is in the interior of PQR , then
mPQR = mPQS + mSQR .

27. mXWZ = 121° and mXWY = 59°.
Find mYWZ.
mYWZ = mXWZ – mXWY
 Add. Post.
mYWZ = 121 – 59
Substitute the given values.
mYWZ = 62
Subtract.

28. KM bisects JKL.
Find mJKM.
(4x + 6)°
(7x – 12)°
mJKM = 30°

29. Bellringer
Have your homework out on your desk! (pg 37 #1-7)

30. Group Work
Work with a table partner on the activity