Divide geometric figures symmetrically and equivalently, in which there are both lines and faces. In order to realize bisection, the region is divided into many corresponding graphics, mainly axisymmetric graphics.

Bisector: Two rays emanating from the vertex of an angle. If an angle is divided into three equal angles, these two rays are called the bisector of the angle.

If it is the bisector of an angle: divide an angle into three parts with two lines, then those two lines are bisectors.

If it is the bisector of side length: divide an edge into three equal points and the connecting line corresponding to the vertex of this edge.

Application definition

An object, a figure and a unit of measurement can all be regarded as the unit "1". Divide the unit "1" into several parts on average, and the number representing such a part or parts is called a fraction. In the fraction, the denominator indicates how many shares the unit "1" is divided into, and the numerator indicates how many shares there are; One of them is called fractional unit.