How to divide a triangle into four parts It's not equilateral

First determine a vertex randomly, mark it as O, find the midpoint of the opposite side of the vertex, and mark it as a,
Connect OA, then find the midpoint of the other two sides from point a, and mark them as B and C respectively,
Connect AB and AC, because the area of the triangle is 1 / 2 of the base times the height,
Finding the midpoint means that their bottom edges are equal in length, so their areas are equal
Using two algorithms is like an apple cut into two parts, and then cut the two parts separately to become four and a half. Just think about it

Please divide each triangle into 3 parts in different ways (isosceles triangle)

1. Divide any side of the triangle into three equal parts, and the line with the vertex can be divided into three equal parts
2. Find out the center of the triangle and connect it with the three angles

How to divide it into three equal parts?

If the three areas are equal, divide the bottom into three parts and connect the vertices

With the help of the triangle ruler, the triangle ruler with 30 ° angle is divided into two triangles in two ways, and one of the triangles is required to be isosceles triangle

In the first method, one side of the 30 ° angle of the triangle ruler is aligned with an edge of the known 30 ° angle of the triangle; then through translation, the other side of the 30 ° angle of the triangle ruler is opposite to the other top angle of the triangle, and then the line is drawn along this edge of the triangle plate

Divide the area of an equilateral triangle into four parts in four different ways

According to the stem analysis, we can get the following conclusions

How to divide an equilateral triangle into four parts Three to four

1. Take the middle vertical line of one corner and fold it in half
Get a triangle, then take the median line. Fold in half
Then there are creases in the four equal shares
2. Take the midpoint of the three sides, and there will be another connection
3. Divide one side into four parts, and connect with the vertex in three ways
4. Make a height, take the vertical point of the height and connect with the midpoint of the other two sides

Divide the area of an equilateral triangle into four parts in four different ways

According to the stem analysis, we can get the following conclusions

How many ways to divide an equilateral triangle into four parts

Connect the midpoint of each side by two

Given that one angle of an isosceles triangle is 80 degrees, then the degrees of the other two angles are respectively?

1. If the top angle is 80 degrees, the two bottom angles = (180 degrees - 80 degrees) × 2 = 50 degrees;
1. If one base angle is 80 degrees, the other base angle is 80 degrees, and the top angle is 180 degrees - 80 degrees × 2 = 20 degrees;

An isosceles triangle, one angle is 40 degrees, and the other two angles are degrees

If the vertex angle is 40 degrees, the degrees of the other two angles are (180 ° - 40 °) / 2 = 70 degrees
If the base angle is 40 degrees, the degrees of the other two angles are 40 degrees and 180 degrees-40 degrees respectively * 2 = 100 degrees

How to divide a triangle into four parts It's not equilateral