I think the answer is A.
It's probably wanting you to use pythagorean theorem.
Answer: $2405
Step-by-step explanation: explanation is in the attached picture file
First, you have to find the equation of the perpendicular bisector of this given line.
to do that, you need the slope of the perpendicular line and one point.
Step 1: find the slope of the given line segment. We have the two end points (10, 15) and (-20, 5), so the slope is m=(15-5)/(10-(-20))=1/3
the slope of the perpendicular line is the negative reciprocal of the slope of the given line, m=-3/1=-3
step 2: find the middle point: x=(-20+10)/2=-5, y=(15+5)/2=10 (-5, 10)
so the equation of the perpendicular line in point-slope form is (y-10)=-3(x+5)
now plug in all the given coordinates to the equation to see which pair fits:
(-8, 19): 19-10=9, -3(-8+5)=9, so yes, (-8, 19) is on the perpendicular line.
try the other pairs, you will find that (1,-8) and (-5, 10) fit the equation too. (-5,10) happens to be the midpoint.
10+(-2)=10-2
Therefore 10-2=8
