# Triangle

Polygons

## Definition

A triangle is a polygon with three sides and three angles.

## Description

Triangles are fundamental shapes in geometry, serving as the building blocks for many complex geometric figures and concepts. Their simplicity and versatility make them crucial in various mathematical and real-world applications. Triangles are classified based on their side lengths and angle measures, leading to categories such as equilateral, isosceles, and scalene triangles, as well as right, acute, and obtuse triangles.

In geometry, triangles play a pivotal role in trigonometry, where the relationships between their sides and angles form the basis for trigonometric functions. These functions are essential in fields like navigation, engineering, and physics. Triangles also feature prominently in architectural design and construction, providing structural stability and aesthetic appeal in buildings and bridges. Their properties, such as the fact that the sum of their interior angles always equals 180 degrees, make them invaluable in problem-solving and proofs across various mathematical disciplines.

For a complete collection of terms related to polygons click on this link: Polygons Collection.

Common Core Standards CCSS.MATH.CONTENT.5.G.B.3, CCSS.MATH.CONTENT.5.G.B.4, CCSS.MATH.CONTENT.3.G.A.1, CCSS.MATH.CONTENT.3.MD.D.8, CCSS.MATH.CONTENT.6.G.A.1, CCSS.MATH.CONTENT.6.G.A.3, CCSS.MATH.CONTENT.HSG.CO.A.3 3 - 8 Geometry     • Polygons         • Definition of a Polygon 2021 polygon, definitions, glossary term