1. It’s Friday!!!  September 6, 2013
Daily Check:
Naming Arcs & Central Angles

2. EOCT Review
Megan is using an equilateral triangle as part of a design on a sweatshirt. Each side of the triangle is 12 inches long. Megan is gluing a line of stars from the midpoint of one side of this triangle to the opposite vertex. Approximately how long will the line of stars be?
13.4
10.4
8.5
5.2 b

3. CCGPS Geometry Day 22 (9-6-13)
UNIT QUESTION: What special properties are found with the parts of a circle?
Standard: MMC9-12.G.C.1-5,G.GMD.1-3
Today’s Question:
What other angle relationships do we know for circles?
Standard: MMC9-12.G.C.2

4. Case I: Vertex is AT the centerP C B

5. Case II: Vertex is ON circle
ANGLE
ARC
ARC
ANGLE

6. Ex. 1 Find m1. 1
84°
m1 = 42

7. 202°
Ex. 2 Find m1. 1
m1 = 79

8. Case III: Vertex is INSIDE circle
ARC B
ANGLE D
ARC C
Be sure to emphasize that the angles is directly across from the arcs…. Big problem last year
Looks like a PLUS sign!

9. Ex. 3 Find m1.
93° A B 1 D C
113°
m1 = 103

10. Ex. 4 Find mQT. N Q
84
92 M T
mQT = 100

11. Ex. 5 Find x.
45
93 xº
89
x = 89

12. Case IV: Vertex is OUTSIDE circle
ANGLE
small ARC A
LARGE ARC D B

13. Ex. 6 Find m1. 1
15° A D
65° B
m1 = 25

14. Ex. 7 Find mAB. A
27°
70° B
mAB = 16

15. Ex. 8 Find m1.
260° 1
m1 = 80

16. Classwork Riddle Worksheet

17. Homework Practice Worksheet