+312 In triangle ABC, the circumcenter and orthocenter are collinear with vertex A. Which of the following statements must be true?
(1) must be an isosceles triangle.
(2) must be an equilateral triangle.
(3) must be a right triangle.
(4) must be an isosceles right triangle.
+312 The answer was actually none of the above, which makes sense if you draw it out.
