Question

Prove that the points (2,-2),(-1,1) and (5,2) are the verticals of right angle triangle.

Answer 1

let A(2,-2) B(-1,1) C(5,2)

use distance formula btw AB ,BC and AC
if ABsquare + Acsquare distance is equal to the distance of AC square then it is right angle triangle

Answer 2

You can simply plot them on a graph or use the distance formula.