Answer:
A. (Orthocenter) → Altitude
B. (Incenter) → Angle bisector
C. (Centroid) → Median
D. (Circumcenter) → Perpendicular bisector
Explanation:
A. The orthocenter is the point of concurrency of the three altitudes of a triangle, therefore, the matching line with the letter A is altitude
B. The incenter is the point of concurrency of the bisectors of three interior angles of a triangle, therefore, the matching line with the letter B is angle bisector
C. The centroid is the point of concurrency of the three medians of the triangle, therefore, the matching line to the letter C is median
D. The circumcenter is the point of concurrency of the three perpendicular bisectors of the three sides of a triangle, therefore, the matching line to the letter D (which corresponds with the circumcenter) is perpendicular bisector.