Thread: Co-ordinates

If you know the equation of a line and the mid-point of a line segment, how do you find the end points?

Is this enough information to be able to find them? I'm supposed to find the vertices B and D of a square ABCD, and I also know the co-ordinates of vertices A and C.

Originally Posted by eechlay

If you know the equation of a line and the mid-point of a line segment, how do you find the end points?

Is this enough information to be able to find them? I'm supposed to find the vertices B and D of a square ABCD, and I also know the co-ordinates of vertices A and C.

From the co-ordinates of A and C find the slope m of the line between them
and their mid point M. Now the other two vertices lie on a line at right
angles to AC (hence of slope -1/m) passing through M. Also the lengths
of MB and MD are equal to MA, which you can find easily.

RonL