Question

56:25

Triangle ABC has vertices at A(–2, 3), B(–3, –6), and C(2, –1). Is triangle ABC a right triangle? If so, which angle is the right angle?

No, the triangle has no right angles.
Yes, the right angle is angle A.
Yes, the right angle is angle B.
Yes, the right angle is angle C.

Answer 1

Yes — the right angle is angle C.

Check with vectors: AC = (4, −4) and BC = (5, 5). Their dot product is 4·5 + (−4)·5 = 20 − 20 = 0, so AC ⟂ BC, meaning angle C is 90°.