Proving Euler's line.?

Question

Euler's the line that goes through the Centroid, Orthocenter and Circumcenter.
Prove that those three points will always be on Euler's line and the incenter will not always be on Euler's line.

Answer 1

That's a tricky proof involving lots of diagrams. We won't be able to reproduce it here, but it will be in your textbook.