1. 12.2 Arcs and
Chords

2. Within a circle or congruent circles, congruent arcs are two arcs that have the same measure. In the figure ST  UV.

4. Example 3A: Applying Congruent Angles, Arcs, and Chords
TV  WS. Find mWS.

5. Example 3B Continued
C  J, and mGCD  mNJM. Find NM.

6. Check It Out! Example 3a
PT bisects RPS. Find RT.

7. Check It Out! Example 3b
Find each measure.
A  B, and CD  EF. Find mCD.

9. Example 4: Using Radii and Chords
Find NP.
Step 1 Draw radius RN.
RN = 17
Radii of a  are .
Step 2 Use the Pythagorean Theorem.
SN2 + RS2 = RN2
SN = 172
Substitute 8 for RS and 17 for RN.
SN2 = 225
Subtract 82 from both sides.
SN = 15
Take the square root of both sides.
Step 3 Find NP.
RM  NP , so RM bisects NP.
NP = 2(15) = 30

10. Check It Out! Example 4
Find QR to the nearest tenth.

11. Assignment Pg. 404 – 405 (15 – 18) (29 – 32) (38 – 39)
Review Worksheet