Vertices of an equilateral triangle Question: show that the following three points in 3D space A = <-2,4,0>, B = <1,2,-1> C = <-1,1,2> form the vertices of an equilateral triangle.
How do i approach this problem?

Apart for showing their length are the same, you will have to show they are not collinear. Construct a line equation with any two given points and check that the remaining point does not lie on the line. The other way is to check the cross product of AB and BC to make sure that it is not equal to 0. :)
