Answer:
112°
Explanation:
Angle A is an inscribed angle that intercepts arc BCD.
Therefore:
m<A = ½ of arc BCD (Inscribed Angle Theorem)
Arc BCD = BC + CD = 146 + CD
An equation can be written to enable us find the measure of arc CD. See below:
Let x = measure of arc CD
Thus,
129° = ½(146 + x)
Solve for x
129*2 = 146 + x
258 = 146 + x
Subtract 146 from both sides of the equation.
258 - 146 = x
112 = x
x = measure of arc CD = 112°