Question

Let A = (−1, 2, 1), B = (−7, 0, 1), C = (−3,−2,−3).
How do you determine if the triangle ABC is right angled? Is it isosceles?

Answer 1

For a triangle be right you must multiply any two vectors. Try multiply A*B. If the product is zero, then the triangle is right.

Answer 2

So I first find the dot product of AB and BC?

Answer 3

Yees

Answer 4

also you could find the length of the edges and see if it satifies pathagorean theorem