Answer:
ST = 9
Explanation:
So, we are given the line segment SU and there is a point T somewhere along it.
That means that the line SU now comprises of two segments: ST and TU, so we can write that down as:
ST + TU = SU
We are also given the lengths of some of these segments; SU = 20 and TU = 11. That means that:
ST + 11 = 20
ST = 20 - 11
ST = 9.
