Question

Show that point (2,1),(5,1),(6,1) are vertices of right angled triangle?

Answer 1

If we graph these three points, we can see they are not part of a right triangle but that all three points lie on the same line.

graph{((x-2)^2+(y-1)^2-0.025)((x-5)^2+(y-1)^2-0.025)((x-6)^2+(y-1)^2-0.025)(y-1)=0 [-10, 10, -5, 5]}