Triangles: Classification, Angles, Sides Lengths

A triangle is a polygon with three edges and three vertices.

1. Equilateral Triangle: All sides are equal. 2. Isosceles Triangle: Two sides are equal. 3. Scalene Triangle: All sides are different.

1. Acute Triangle: All angles are less than 90 degrees. 2. Right Triangle: One angle is exactly 90 degrees. 3. Obtuse Triangle: One angle is greater than 90 degrees.

The sum of the interior angles in a triangle is always 180 degrees.

Subtract the sum of the known angles from 180 degrees.

An equilateral triangle is a triangle in which all three sides are of equal length and all three angles are equal to 60 degrees.

An isosceles triangle has at least two sides that are equal in length and the angles opposite those sides are equal.

A scalene triangle has all sides of different lengths and all angles of different measures.

A right triangle is a triangle that has one angle measuring exactly 90 degrees.

An acute triangle is a triangle where all three angles are less than 90 degrees.