Equilateral  Triangle  :   A triangle whose all the sides are equal in length ( or congruent ), is called an equilateral triangle.

  Isosceles  Triangle  :   A triangle whose only two sides are equal in length ( or congruent ), is called an isosceles triangle.

  Scalene  Triangle  :   A triangle whose none of the sides are equal in length ( or not congruent ), is called an equilateral triangle.

  Acute–angled  Triangle  :   A triangle whose all the angles are acute, is called an acute-angled  triangle or an acute triangle.

  Right–angled  Triangle  :   A triangle whose one angle is a right angle, is called  a right-angled triangle or a right triangle.

  Obtuse–angled  Triangle  :   A triangle whose one angle is obtuse, is called an obtuse-angled triangle or an obtuse triangle.

Click here to next topic