Answer:
x = 30
Step-by-step explanation:
The measure of the chord- chord angle is one half the the sum of the arcs intercepted by the angle and its vertical angle, that is
A
[tex]\frac{1}{2}[/tex] (2x + 10 + x + 20) = 60
B
Multiply both sides by 2 to clear the fraction
2x + 10 + x + 20 = 120, that is
3x + 30 = 120 ( subtract 30 from both sides )
3x = 90 ( divide both sides by 3 )
x = 30
