Question

Which type of triangle is formed by joining the vertices A(-3, 6), B(2, 1), and C(9, 5)?

Answer 1

Find the lengths AB, BC and AC.
length AB= √(4²+(-4)²) = √32 
length BC = √(4²+7²) = √65
length AC = √(8²+3²) = √73

From the lengths of this triangle it can be seen that no side is equal to the other and also it is not a right triangle. 

So, triangle ABC is a scalene.