Answer: ST = 9
Concept:
Here, we need to know the idea of the segment addition postulate.
The Segment Addition Postulate states that given 2 points A and C, a third point B lies on the line segment AC if and only if the distances between the points satisfy the equation AB + BC = AC.
Solve:
Given information
TU = 11
SU = 20
Given expression deducted from the segment addition postulate
ST + TU = SU
Substitute values into the expression
ST + 11 = 20
Subtract 11 on both sides
ST + 11 - 11 = 20 - 11
Hope this helps!! :)
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