Perpendicular Lines

Question

The vertices of a triangle are labeled clockwise A(–5, 3), B(6, 1), and C(–2, –3). How could you show that the figure is a right triangle?

 

Answer 1

BC has slope = 1/2

AC has slope = -2

their slopes are negative inverses so ABD is a right triangle

or show AB^2 = AC^2 + BC^2