1. Divide one side into four parts evenly, and connect the three equal points with the vertex angles respectively. ?

2. Take the midpoint of three sides and connect them in turn.

3. Take the midpoints of three sides, one of which is connected to the same vertex and the other two midpoints. ?

4. Take the center line of the bottom edge, take the midpoint of the center line and connect it with the two bottom corners. ?

5. Take the center line of the bottom edge, connect the midpoint on the left side of the bottom edge with the vertex angle, and connect the midpoint of the right adjacent edge with the midpoint of the bottom edge. Only the second one is the same shape.

The area of a triangle with equal base and height is equal and the application of this knowledge.

Triangle (triangle)

It is a closed figure composed of three line segments in the same plane but not on the same straight line, which has applications in mathematics and architecture.

Ordinary triangles are divided into ordinary triangles (three sides are unequal) and isosceles triangles (isosceles triangles with unequal waist and bottom and isosceles triangles with equal waist and bottom, that is, equilateral triangles); According to the angle, there are right triangle, acute triangle and obtuse triangle, among which acute triangle and obtuse triangle are collectively called oblique triangle.

A closed figure composed of three line segments that are not on the same straight line is called a triangle. A figure surrounded by three straight lines on a plane or three arcs on a sphere is called a plane triangle; A figure surrounded by three arcs is called a spherical triangle, also known as a triangle.

A closed geometry consisting of three line segments connected end to end is called a triangle. Triangle is the basic figure of geometric figure.