We've learned about the composition of triangles. What are the elements

Three points, three lines, three angles

What is this line of the triangle called?
The middle points of AB and AC on both sides of the triangle ABC are D and e respectively, connecting de. what is the segment De of the triangle?

Median line, come on, learn

Each line surrounding the triangle is called the side of the triangle, and () of each two line segments is called the vertex of the triangle

Each line of a triangle is called its edge, and the intersection of two lines is called its vertex

A triangle is formed by the opposite extension of one side of a triangle angle and the other side?

The angle formed by the extension of one side and the other side of a triangle is called the outer angle of the triangle
The sum of the external angles of a triangle is 360 degrees

What is a triangle

A closed figure composed of three line segments which are not on the same line and are connected in sequence is called a triangle. The figure enclosed by three lines on a plane or three arcs on a sphere is called a plane triangle. The figure enclosed by three arcs is also called a spherical triangle, also called a triangle

What triangle is called equilateral triangle, also called triangle

A triangle with three equal sides is called an equilateral triangle or an isosceles triangle

Triangles with three equal sides are called equilateral triangles or triangles

Regular triangle

What kind of triangle is called isosceles? What kind of triangle is called equilateral triangle? What kind of triangle

A triangle with two equal sides is called an isosceles triangle
A triangle with three equal sides is called an equilateral triangle
Equilateral triangle is a special isosceles triangle

Equilateral triangles are also called Triangle, each inner angle is equal to °．

An equilateral triangle is also called an equilateral triangle. Because the three internal angles of an equilateral triangle are equal, the degree of each internal angle is 180 ° 3 = 60 °. So the answer is: positive, 60

A triangle with three equal sides is called an equilateral triangle
A theorem
B km
C definition
D inverse proposition

C definition, because it says "what is an equilateral triangle"

We've learned about the composition of triangles. What are the elements