Posts from Triangle!

Another question has arisen: which is the most stable figure? In theory, it's a tetrahedron, but I asked my friend the question slightly incorrectly: which is the most stable geometric figure? The answer was: a triangle Since a triangle is a figure in a plane, I tried to explain to him that a triangle cannot be called stable because it does not have width + length + height, so it cannot "stand". Is a tetrahedron a geometric figure? If not, can a geometric figure be stable, and if so, which one?

Both a tetrahedron and a triangle are geometric shapes. The difference is that a tetrahedron is a stereometric figure, while a triangle is a planimetric figure. Any stereometric figure is more or less stable, while planimetric figures are not.

A triangle is a geometric figure consisting of three points that do not lie on the same line, and three line segments that connect these points in pairs.

The word "pairs" in the definition should not be there. A pair is two, but there are three.

Haha, I'm reading this and laughing:smile52:
There are still other opinions – it just means the debate hasn't been settled yet.

You can touch the material embodiment of a triangle.
Of course, you can't touch the immaterial one; after all, a triangle is just a conventional designation for a specific space or shape.
However, if it isn't drawn (cast/carved/molded) somewhere, it doesn't exist in matter. Therefore, a triangle is truly an astral and all-powerful thing beyond the understanding of ordinary people.