orthocenter of a triangle

Step 1. Set the compass width to the length of a side of the triangle 2. From B draw an arc across AC creating point F. 3. From C draw an arc across BA creating point P 4. Set the compass width to more than half the distance BP. 5. From B and P, draw arcs that intersect at point Q 6. With a straightedge on C and Q, draw an altitude of the triangle 7. Set the compass width to more than half the distance CF. 8. From C and F, draw arcs that intersect at point E 9. With a straightedge on B and E, draw another altitude of the triangle Done. The intersection of the altitudes is the orthocenter of the triangle