1. 12.3
Inscribed Angles

2. 12.3 – Inscribed Angles
The vertex of C is on O, and the sides of C are chords of the circle.
C is an inscribed angle
AB is the intercepted arc C B A

3. 12.3 – Inscribed Angles
How to find the inscribed angle if you know the arc length
m B = mAC 1 2 B C A

4. 12.3 – Inscribed Angles
Find a and b P Q R S T
60°
30° b° a°

5. 12.3 – Inscribed Angles
2 inscribed angles that intercept the same arc are congruent.
38°
70° x

6. 12.3 – Inscribed Angles
An angle inscribed in a semicircle is a right angle
40°
70° x

7. 12.3 – Inscribed Angles
The opposite angles of a quadrilateral inscribed in a circle are supplementary
60°
80° 1 2 3 4

8. 12.3 – Inscribed Angles
The measure of an angle formed by a tangent and a chord is half the measure of the intercepted arc.
m C = mBDC 1 2 B C D B C D

9. 12.3 – Inscribed Angles KJ is tangent to circle J. Find x and y K x°
35° y° x°