Use the converse of the pythagorean theorem to determine whether the triangle with the given vertices is a right triangle. (2, 1) (6, 4), (-4, 9)

Hello:

let : A (2, 1), B (6, 4), C (-4, 9)

calculate : AB, AC, BC

AB = √ ((6-2) ² + (4-1) ²) = √25 = 5

AC = √ ((-4-2) ² + (9-1) ²) = √100 = 10

BC = √ ((-4-6) ² + (9-4) ²) = √125

by pythagorean theorem : BC² = AC² + AB²

the triangle is rectangle in : A