The three median lines of a triangle intersect at a point, which is called the center of gravity of the triangle.

The perpendicular lines of the three sides of a triangle intersect at a point, which is called the outer center of the triangle.

The three heights of a triangle intersect at a point. This point is called the vertical center of the triangle.

The bisectors of the three internal angles of a triangle intersect at a point, which is called the center of the triangle.

The bisector of the inner corner of a triangle and the bisector of the outer corner intersect at one point at the other two vertices. This point is called the center of the triangle. A triangle has three side centers.

Only equilateral triangles have centers. Center of gravity, center of gravity, center of gravity and center of gravity coincide, which is called center.