# Triangles

## Triangles in Geometry:

A triangle is a polygon with three sides, three vertices, and three angles. Triangles are fundamental geometric shapes and play a crucial role in geometry. They are classified based on side lengths and angle measures.

### Classification of Triangles:

By Side Lengths:

Equilateral Triangle: All three sides of an equilateral triangle are of equal length.

Isosceles Triangle: In an isosceles triangle, at least two sides are of equal length.

Scalene Triangle: All three sides have different lengths in a scalene triangle.

By Angle Measures:

Acute Triangle: All three angles of an acute triangle are less than 90 degrees.

Right Triangle: A right triangle has one angle measuring exactly 90 degrees.

Obtuse Triangle: In an obtuse triangle, one angle is greater than 90 degrees.

Special Cases:

Equiangular Triangle: An equiangular triangle has all three angles equal.

Degenerate Triangle: A degenerate triangle has collinear vertices, meaning the three vertices lie on the same straight line.

Straight Angle: An angle that measures exactly 180 degrees, forming a straight line.

Reflex Angle: Â An angle that measures more than 180 degrees but less than 360 degrees.

Full Angle (Complete Angle): An angle measuring 360 degrees forms a complete circle.

Adjacent Angles: Two angles are adjacent if they share a common arm and vertex but have no common interior points.

These examples and drawings illustrate various types of angles, their measurements, and relationships. Understanding angles is essential for solving geometric problems, describing shapes, and analyzing spatial configurations.

Triangles are versatile geometric shapes with properties and classifications that are fundamental to understanding geometry. They are extensively used in various mathematical and scientific applications.