Answer
Each angle is equal to half of the length of the arc that it corresponds to. Angle R and angle T correspond to arcs that add up to the whole circle, so the sum of their measures is equal to one half of 360 degrees, which is 180 degrees. Likewise, angle V and angle S correspond to arcs that add up to the whole circle, so the sum of their measures is equal to one half of 360 degrees, which is 180 degrees. Thus, the sum of angle R and angle T is equal to the sum of angle V and angle S, for both sums equal 180 degrees.
