If T is the midpoint of SU, what are ST, TU, and SU?
a. ST = 8, TU = 40, and SU = 80
b. ST = 10, TU = 10, and SU = 20
c. ST = 54, TU = 54, and SU = 108
d. ST = 40, TU = 40, and SU = 80
