# Math Help - vectors 4

1. ## vectors 4

[Note: A right-angled triangle is a triangle with one 90o internal angle.]

Vector AB is ( 3, 6 , 1)
Vector BC is ( 0 , -7 , -4)
Vector CA is ( -3 , 1 , 3)

2. Originally Posted by daphnewoon
[Note: A right-angled triangle is a triangle with one 90o internal angle.]

Vector AB is ( 3, 6 , 1)
Vector BC is ( 0 , -7 , -4)
Vector CA is ( -3 , 1 , 3)
Take the three dot products, see if one of them is 0.

3. the x part is zero. thus it is a right-angled triangle?

4. No.

Do what I said.

Find $A\cdot B$, $A\cdot C$ and $B\cdot C$, and see if any of these dot products are 0. If so, you have a right angle.

If you do not know anything about dot products (also known as scalar products) I suggest you do a Google search.