If triangle abc defined by the coordinates a(1, 1), b(9, 1), c(1, 9) is dilated by a scale factor of 1 2 , with resulting vertex b' at (5, 1), what is the center of the dilation?

the answer is b (1, 1)

In this case, the center of dilation is a vertex of the original figure.  

The center of dilation is a fixed point in the plane about which all points are expanded or contracted.

Step-by-step explanation:

true? is that what you're asking or do you mean something else?

square root

step-by-step explanation: