This is my first post. I graduated from mathematics in university 16 years ago so I am somewhat out of practice. I recently ran into my high school teacher from several years ago and he posed a math problem to me. I need some help with it, even a push in the right direction. Thanks. Here is the problem:

A line segment has its endpoints on the x and y axes.

The line segment passes through point (6,6).

The line segment's length is 21.

Determine the unknown points on the x and y axes.

Thanks

Norm F