Regina G. answered 05/30/14
Tutor
5.0
(322)
Biotech Grad with Homeschool Experience, Math and Science Focus
Well, I'm sure you know that you need to draw out the triangle and the altitudes of the triangle.
The orthocenter is where the lines of altitude intersect. If they don't intersect inside the triangle, you need to extend the lines with a ruler or straightedge, until they do.
Even if the lines intersect outside of the triangle, the point at which they intersect is still the orthocenter.