Medical Definition of Snellen chart. : the chart used in the snellen test with black letters of various sizes against a white background.
The circumcenter, the incenter is the point of concurrency of the angle bisectors of a triangle.
One of a triangle's points of concurrency. Try this Drag the orange dots on any vertex to reshape the triangle. Notice the location of the orthocenter. The altitude of a triangle (in the sense it used here) is a line which passes through a vertex of the triangle and is perpendicular to the opposite side.