1. Apply other angle relationships in circles
10.5

2. Remember…
The measure of an inscribed angle is half the measure of the arc.
92º
46º

3. Something new
The angle created by the tangent and a chord is half the measure of the arc.
Or we can say that the arc is twice the measure of the angle created.

5. Find the measures of the 2 angles
230º

6. Find the measures of the arcs
110º
250º

7. Angles inside a circle theorem
If 2 chords intersect to make an X inside a circle, then half the sum of the opposite arcs equals the measure of the angle.

8. Find the value for x ?

9. Find the value for y
78°

10. Find the value of x
.5(x+45)=57.5
57.5
x+45=115
x=70

11. Angles outside the circle theorem
Larger arc – smaller arc, then divide by 2 to get the measure of the angle

12. Find the value of x

13. Find the value of a

14. Find the value of x
=128°
232
Hmmmm…

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