1. -Warm Up 2.2 on Desk (10 minutes) -Do the Daily Quiz 2.1 01/16/17

2. Warm Up
Lesson Presentation
Lesson Quiz
Homework

3. - How do you bisect an Angle?
ESSENTIAL QUESTION:
- How do you bisect an Angle?

7. <ABD is congruent to <CBD

8. BD bisects ABC, and mABC = 110°. Find mABD and mDBC.
Example 1
Find Angle Measures
BD bisects ABC, and mABC = 110°.
Find mABD and mDBC.
SOLUTION 2 1
(mABC)
mABD = 2 1 =
(110°) =
55°
ABD and DBC are congruent,
ANSWER
So, mABD = 55°, and mDBC = 55°. 8

9. HK bisects GHJ. Find mGHK and mKHJ.
Checkpoint
Find Angle Measures
HK bisects GHJ. Find mGHK and mKHJ. 2. 1. 3.

10. HK bisects GHJ. Find mGHK and mKHJ.
Checkpoint
Find Angle Measures
HK bisects GHJ. Find mGHK and mKHJ. 1.
ANSWER
26°; 26° 2.
ANSWER
45°; 45° 3.
ANSWER
80.5°; 80.5°

11. Checkpoint
Find Angle Measures and Classify an Angle
QS bisects PQR. Find mSQP and mPQR. Then determine whether PQR is acute, right, obtuse, or straight. 5. 4. 6.

12. Checkpoint
Find Angle Measures and Classify an Angle
QS bisects PQR. Find mSQP and mPQR. Then determine whether PQR is acute, right, obtuse, or straight. 4.
ANSWER
29°; 58°; acute 5.
ANSWER
45°; 90°; right 6.
ANSWER
60°; 120°; obtuse

13. The measure of DAB is 90°, and the measure of BCD is 54°. ANSWER
Example 3
Use Angle Bisectors
In the kite, DAB is bisected AC, and BCD is bisected by CA. Find mDAB and mBCD.
SOLUTION
2(mABC)
mDAB = =
2(45°) =
90°
2(mACB)
mBCD = =
2(27°) =
54°
The measure of DAB is 90°, and the measure of BCD is 54°.
ANSWER 13

14. Checkpoint 7. KM bisects JKL. Find mJKM and mMKL. ANSWER 48°; 48°
Use Angle Bisectors 7.
KM bisects JKL.
Find mJKM and
mMKL.
ANSWER
48°; 48° 8.
UV bisects WUT.
Find mWUV and
mWUT.
ANSWER
60°; 120°

15. Use Algebra with Angle Measures
Example 4
SOLUTION
mPRQ =
mQRS
Use Algebra with Angle Measures
RQ bisects PRS. Find the value of x. =
85°
(6x + 1)° =
85 – 1
6x + 1 – 1
6x = 84 6x 6 –– = 84
x = 14
You can check your answer by substituting 14
for x.
mPRQ = (6x + 1)° = (6 · )° = (84 + 1)° = 85°
CHECK 15

16. BD bisects ABC. Find the value of x.
Checkpoint
Use Algebra with Angle Measures
BD bisects ABC. Find the value of x. 9.
10.

17. BD bisects ABC. Find the value of x.
Checkpoint
Use Algebra with Angle Measures
BD bisects ABC. Find the value of x. 9.
ANSWER 43
10.
ANSWER 3

18. Review
On Daily Quiz 2.1

19. FH
1. Line bisects Find GH and FH.
GH = 27.5, FH = 55
ANSWER
2. M is the midpoint of AB. Find the value of x.
ANSWER
x = 5

20. Find the coordinates of the midpoint of the segment whose endpoints are P(–2, –3) and Q(2, 7).3.
M(0, 2)
ANSWER
Julia is hiking a trail that is 3.4 miles long. She plans to stop for lunch when she reaches the halfway point on the trail. How far will she hike before stopping to eat her lunch? 4.
ANSWER
1.7 miles

21. HOMEWORK (Bractice B)