We can make a drawing to see better:
7) We know that RM = 4 and MS = 9, so:
The answer is TM = 20.25
8) We know that RS = 20 and RM = 8, so:
The answer is RT = 50.
9) We know that RM = 5 and MS = 7, so:
The answer is TS = 12.043
10) We know that RM = 1/2 and MS = 1/4, so:
The answer is RT = 5/8 = 0.625