Reflection across the y-axis
If it bisect, then using the Line Bisector Theorem, it must be equal.
So x+6=4x-21
get like terms on 1 side
x+6=4x-21
-x. +21
27= 3x
x=9
plug the x in
CD= 9+6
CD=15
13.5 inches, because if you add 4.5x4 or 9x2 it equals 18, then you just subtract 4.5 from 18 and it’s 13.5
Answer:
don't know
Step-by-step explanation: