Based on their angles, the 3 types of triangles are listed as, acute triangle, obtuse triangle, and right-angled triangle. Based on their sides, the 3 triangles are classified as equilateral triangles, isosceles triangles, and scalene triangles. sides and angles and are of six types in total. Triangles are classified according to 2 groups i.e. Listed below are a few topics related to classifying triangles, take a look!įAQs on Classifying Triangles What is the Classification of Triangles in Geometry? Acute Scalene Triangle : A triangle that has 3 unequal sides and 3 acute angles is called an acute scalene triangle.Obtuse Scalene Triangle : A triangle with an obtuse angle with sides of different measures is called an obtuse scalene triangle.Right Scalene Triangle : A triangle in which any one of the angles is a right angle and all the 3 sides are unequal, is called a right scalene triangle.Acute Isosceles Triangle : A triangle in which all 3 angles are acute angles and 2 sides measure the same is called an acute isosceles triangle.Obtuse Isosceles Triangle : A triangle in which 2 sides are equal and one angle is an obtuse angle is called an obtuse isosceles triangle.So, in an isosceles right triangle, two sides and two acute angles are congruent. Isosceles Right Triangle: A triangle in which 2 sides are equal and one angle is 90° is called an isosceles right triangle.Equilateral or Equiangular Triangle: When all sides and angles of a triangle are equal, it is called an equilateral or equiangular triangle.The different types of triangles are also classified according to their sides and angles as follows: The side opposite to the obtuse angle is considered the longest.Ĭlassification of Triangles Based on Angles and Sides Obtuse TriangleĪn obtuse-angled triangle or obtuse triangle is a type of triangle whose one of the vertex angles is bigger than 90° and the sum of the other two angles is less than 90°. The side opposite to the right angle is the largest side and is referred to as the hypotenuse. Here, the relationship between the sides is understood with the help of the Pythagoras rule. A 90-degree angle is called a right angle, and hence the triangle with a right angle is called a right triangle. Right TriangleĪ right-angled triangle is a triangle with one of the angles as 90 degrees. The sides of an acute-angled triangle can be equal or unequal depending on whether the triangle is equilateral, isosceles, or scalene. Acute TriangleĪcute triangle is a type of triangle where all three interior angles are acute angles or less than 90°. The three different types are acute triangle, obtuse triangle, and right triangle. All triangles have three interior angles whose angle measurements sum to 180° with different combinations of angles depending on the type of triangle. Triangles can also be classified on the basis of angles. no matter where a line is drawn through a scalene triangle, the left and right sides of the line will never be equal to each other.Ĭlassification of Triangles Based on Angles

This shape does not have a line of symmetry i.e. Scalene TriangleĪ scalene triangle is a triangle with all three sides of different lengths along with three angles of different measures. The two equal sides of an isosceles triangle are called the legs and the angle between them is called the vertex angle or apex angle. This type of triangle has two sides of the same length. The word isosceles is derived from the Greek word 'iso' which means same and 'skelos' which means leg. An equilateral triangle is considered a regular polygon with angles and sides equal. Here, the three sides are equal to each other along with the three angles measuring 60°. Equilateral TriangleĮquilateral triangle is the most common type used while learning the basics of the shape.

The three types of triangles are equilateral triangle, scalene triangle, and isosceles triangle. Hence, triangles are classified on the number of sides with the same length equal to each other or not equal at all.

It is specifically based on the ratio of the lengths of the sides with one another rather than the unit measure. Classification of Triangles Based on SidesĪ triangle consists of three sides but the factor to classify them is the length of the sides.

Triangles scalene isosceles equilateral