1. Inscribed Angles Pick up Purple Paper
There is no quiz or test, I didn’t feel like moving desks…

2. Learning target: Find measures of inscribed angles, and inscribed polygons.
In class: notes/exit slip
HW: organize notebooks
Warm-up 4/15 B
35° A
2cm
1. Find the measure of arc AB
2. Find the arc length of AB

3. Key Definitions
An angle formed by two chords with a vertex on the circle is an inscribed angle.
An arc between the intersection of the sides of an inscribed angle and the circle is an intercepted arc.
Inscribed Angle
Intercepted Arc

4. Are the following angles circumscribed or inscribed angles?

5. Inscribed Angle Theorem
The measure of an inscribed angle is half the measure of its intercepted arc.

6. Angle A’s intercepted arc is a semicircle.
Since it’s a semicircle, its intercepted arc measure is 180.
𝑚∠𝐴=90°

8. True
False
True
False
True

9. What are the values of a and b?
𝑚∠𝑃𝑄𝑇= 1 2 𝑚 𝑃𝑇
60= 1 2 a
120= a
𝑚∠𝑃𝑅𝑆= 1 2 (𝑚 𝑃𝑇 +𝑚 𝑇𝑆 )
𝑏= 1 2 (120+30)
𝑏=75

10. Find the measure of the numbered angles
𝑚∠1=𝑚∠3=90°
𝑚∠4= 1 2 (60+80)
𝑚∠4=70
𝑚∠2=180−70
𝑚∠2=110

11. Now You Try! Find the Variables
c = 90
p = 90
q = 122