Q27:
R, S, T, and U are points on a line, and U is the midpoint of line segment ST. If the lengths of line segments RS, RT, and ST are 20, 4, and 24, respectively. What is the length of line segment RU?
A. 6
B. 8
C. 12
D. 14
E. 16
The answer is B...請好心人幫幫我吧~