How do you solve for r, please show steps
(r-2)^2 + (8 - r)^2 = (r + 2)^2
expand, simplify, then write it in standard form
r^2 - 4r + 4 + 64 - 16r + r^2 = r^2 + 4r + 4
r^2 -24r +64 = 0
solving by completing the square, easiest way in this case.
r^2 - 24r + 144 = 144 - 64
(r-12)^2 = 80
r-12 = ±√80
r = 12 ± 4√5