MathDB

The orthocenter of triangle

ABC

lies on its circumcircle. One of the angles of

ABC

must equal: (The orthocenter of a triangle is the point where all three altitudes intersect.)

\mathrm a. ~ 30^\circ\qquad \mathrm b.~60^\circ\qquad \mathrm c. ~90^\circ \qquad \mathrm d. ~120^\circ \qquad \mathrm e. ~\text{It cannot be deduced from the given information.}

Problem Statement