Answer:
D = 130
Step-by-step explanation:
We can use the formula
<Y = 1/2 (big arc XZ - little arc XZ)
50 = 1/2 ( 230- XZ)
Multiply by 2 on each side
100 = 230-XZ
Subtract 230 from each side
100-230 = 230-230 -XZ
-130 = -XZ
Multiply each side by -1
-1*-130 = -1 * -XZ
130 = XZ
