Triangle

A triangle is a geometric shape with three sides and three angles. It is a basic building block in geometry and can be classified based on its sides (equilateral, isosceles, or scalene) or angles (acute, right, or obtuse). Triangles are fundamental because they can be used to analyze shapes and structures, and they follow specific rules such as the sum of interior angles always equaling 180 degrees. They are widely used in construction, engineering, and design due to their strength and stability in structural applications.