Answer:
x = 100degrees
Explanation:
Using the theorem;
The angle at the vertex is the half of the difference of its intercepted arcs
Angle at the vertex = 15 degrees
angle at the intercepted arcs = 70degrees and x degrees
According to the theorem;
15 = 1/2(x-70)
Cross multiply
15 * 2 = x - 70
30 = x - 70
Add 70 to both sides
30 + 70 = x - 70 + 70
100 = x
Swap
x = 100degrees
Hence the value of x is 100degrees
