Question

condition to form a triangle

Answer 1

Answer:

Condition on the sides

The triangle inequality states that the sum of the lengths of any two sides of a triangle must be greater than or equal to the length of the third side. That sum can equal the length of the third side only in the case of a degenerate triangle, one with collinear vertices.

Edges and vertices: 3

Internal angle (degrees): 60°

Dual polygon: Self

Symmetry group: Dihedral (D3), order 2×3