Types of Triangles: Definition and Examples

Mathematically, a three-angled figure is considered to be a triangle. In many parts of the world, it is referred to as a trigon. The word is taken from the Greek word ‘tri’, which means three. Every triangle has three sides and three angles, but they exist in various sizes and forms. Triangles can be classified based on their angles and sides, and knowing these features helps you apply the concepts to a set of innovative real-life problems. Below mentioned are the types of triangles based on two important parameters; they are classified into the following: Based on the Sides of a triangle

• Equilateral Triangle: A triangle having all three sides of equal length is known as an equilateral triangle.
• Isosceles Triangle: An isosceles triangle is one having any two sides of equal length and the angles opposite to the equal sides as equal.
• Scalene Triangle: A triangle with all three sides of distinct sizes or lengths is called a scalene triangle.

Based on the degree of the angles of a triangle:

• Acute Triangle: When the measure of all the angles inside a triangle is less than 90 degrees, it is termed an acute-angled triangle.
• Obtuse Triangle: When the measure of anyone the angles inside a triangle is more than 90 degrees, it is termed an obtuse-angled triangle.
• Right-angle Triangle: When the value of one of the angles inside a triangle is exactly equal to 90 degrees, it is termed an acute-angled triangle. The remaining two angles inside the triangle are of acute value.
   

Know all about Area of Triangle Formula to solve exam questions. 

Based on Both Sides and Angles:

When we combine the properties of the triangles mentioned above, we are exposed to an entirely different set of triangles consisting of values matching both sides and angles. So let us dig deep into such types of triangles:

• Isosceles Right Triangle: An isosceles right-angled triangle combines the properties of an isosceles triangle and a right-angled triangle. It is a triangle having two equal sides and the angle subtended by these lines is exactly equal to 90-degrees.
• Obtuse Isosceles Triangle: An obtuse isosceles triangle combines the properties of an obtuse triangle and isosceles triangle. It is defined as a triangle having two sides as equal and the angle extended by them is an obtuse angle.
• Acute Isosceles Triangle: In a triangle where all the three angles inside are acute angles, two sides have identical sizes; it is called an acute isosceles triangle. An acute isosceles triangle combines the properties of acute as well as an isosceles triangle.
• Right Scalene Triangle: A right scalene triangle combines the properties of a right- angled triangle and a scalene triangle. All the sides are unequal, and one of the angles measures 90 degrees in such types of triangles.
• Obtuse Scalene Triangle: An obtuse scalene triangle combines the properties of an obtuse triangle and a scalene triangle. A triangle with an obtuse angle and all three distinct sides is called an obtuse scalene triangle.
• Acute Scalene Triangle: An acute scalene triangle combines the properties of an acute triangle and a scalene triangle. Such types of triangles contain three uneven sides with all three angles as acute angles.