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= √((2--3)²+(1-6)²) = √(5²+(-5)²) = √50length BC = √((5-1)²+(9-2)²) = √(4²+7²) = √65length AC = √((9--3)²+(5-6)²) = √(12²+1²) = √145

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.