What are the properties of the triangle?

The properties of the triangle :

A triangle is a polygon with three edges and three vertices. It is one of the basic shapes in geometry. 

The properties of the triangle are:

• Area of a triangle $= \frac{1}{2} \times base \times height$.
• The perimeter of a triangle is the sum of all its three sides.
• The sum of all the angles of a triangle is equal to 180 degrees.
• The sum of the length of the two sides of a triangle is greater than the length of the third side.
• The difference between the two sides of a triangle is less than the length of the third side.
• The side opposite the greater angle is the longest side of all the three sides of a triangle.
• The exterior angle of a triangle is always equal to the sum of the interior opposite angles (Exterior angle property).
• Two triangles are said to be similar if their corresponding angles of both triangles are congruent and the lengths of their sides are proportional.
• Two triangles are congruent if their corresponding sides are equal in length, and their corresponding angles are equal in measure.