Question

is triangle XYZ with vertices X(-3,1), Y(2.4), Z(2.-5) a scalene triangle?

Answer 1

what are the lengths of the sides?
If they are all different, it is scalene.
You can just do the squares of the lengths, no need to take the square roots.
in general:

length^2 = (X2-X1)^2 + (Y2-Y1)^2

Answer 2

for example the length from X to Y:
XY^2 = (2 - -3)^2 + (4 - 1)^2

= 5^2 + 3^2

= 25 + 9

= 34 is the square of length XY

Answer 3

A triangle XYZ has vertices X(1,1),Y(3,1),and Z(2,4).Find The equilateral triangle