Geometry
# 2D Coordinate Geometry

$ABC$ is a right triangle with $\angle ABC = 90 ^ \circ$.

If $A = ( 4, 9 )$ and $B = ( 11, 14)$, which of the following is a possible coordinate for $C$?

The point $P:(4, -26)$ is reflected across the origin, and now becomes the point $P':(a,b)$.

What is $a + b$?