A triangle is a polygon with three sides, three vertices (corners), and three angles. Triangles can be classified based on the lengths of their sides and the measures of their angles as follows:
By Side Lengths:
Equilateral Triangle: All three sides are equal in length.
Isosceles Triangle: Two sides are equal in length.
Scalene Triangle: All three sides have different lengths.
By Angle Measures:
Acute Triangle: All three angles are less than 90 degrees.
Right Triangle: One angle is exactly 90 degrees.
Obtuse Triangle: One angle is greater than 90 degrees.
The sum of the interior angles of any triangle always adds up to 180 degrees.