Answer:

Lines which have a point in common are said to be concurrent. In geometry, three or more lines are said to be concurrent if they intersect at a single point. In a triangle, four basic types of concurrent lines are altitudes, angle bisectors, medians, and perpendicular bisectors.

• In a triangle, altitudes run from each vertex and meet the opposite side at right-angles. The point where three altitudes meet is the orthocenter
• Angle bisectors are rays running from the bisector of each angle of the triangle. They all meet at the incenter.
• Medians connect the vertexes in a triangle to the midpoint of the opposite side. They meet at the centroid
• Perpendicular bisectors are lines running out of the midpoint of each side in a triangle at 90 degree angles. They meet at the circumcenter.