A triangle.
That is the definition of a triangle. If it did not have three sides it would not be a triangle. If it did not have three angles, it would not be a triangle.
A triangle.
A triangle with three sides is a polygon.
An equilateral triangle is a triangle in which all three sides are equal. An example is a triangle with 60o in all three corners.
It impossible for a triangle to have three acute angles. * * * * * What? A triangle most certainly can have three acute angles. Such a triangle would be called an acute-angled triangle!
A triangle with three equal sides and three equal angles is called an equilateral triangle.
triangle
There are three straight edges in a triangle.
A triangle with three congruent angles
a triangle is a polygon with three sides.
Three is to triangle as eight is to octagon.
Every triangle has three sides. If it has any number of sides other than three, then it isn't a triangle.