Answer:
96 degrees
Step-by-step explanation:
Since you know that arc are twice the angle measure, that means arc RT is 42 * 2 = 84. Then, you have to find the measure of RS.
Remember that arc RT and RS have to add up to 180 degrees because they form a semicircle (half of a circle).
To find the measure of RS, just do 180 - 84 = 96 degrees.
