As follows:
The triangle area formula refers to the area of the triangle calculated by the formula. A closed figure composed of three line segments on the same plane but not on the same straight line is called a triangle with the symbol △.
Common triangles are divided into isosceles triangles (isosceles triangles with unequal waist and bottom and isosceles triangles with equal waist and bottom) and isosceles 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.
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.