It is a special method to find the triangle area, which mainly solves the problem of oblique triangle area. The specific formula is: the area of triangle is equal to half of the product of horizontal width and plumb height.
The so-called vertical height and horizontal width should be terms of physics or architecture. The horizontal width of a triangle refers to the horizontal distance between two vertices, while the vertical height refers to the vertical height from one vertex to the opposite side or extension line.
When a vertex of a triangle moves on a straight line, we need to find the three-point line first, and then discuss it on both sides. With the help of auxiliary lines (vertical lines or horizontal lines), it is transformed into a calculated figure, and the area of a triangle is represented by an unknown number, and then the equation (or inequality) is solved according to the requirements of the topic.
The method of finding triangle area in coordinate system is similar to that in geometry. Excavation and filling method ("irregular" triangle, that is, triangle with unknown base height), area method (regular triangle), plumb hammer method and transformation method (triangle with the same base height has the same area).
Introduction to triangle:
Triangle is a closed figure composed of three line segments on 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.