b)
To find angle RST, we would apply the theorem which states that the angle subtended at the circumference of a circle by 2 intersecting chords is equal to half the intercepted arc. This means that
angle RST = arc RT/2
From the information given,
arc RT = 22
angle RST = 22/2
angle RST = 11 degrees
c)
The angle formed between the tangent and the diameter of the circle is 90 degrees. This means that
angle WSR = 90 degrees
angle WST = angle RST + angle WSR
angle WST = 11 + 90
angle WST = 101 degrees
