Classifying Triangles Worksheet

Once your child has learnt about triangles, help them learn to classify triangles with this classifying triangles worksheet. Kids start learning about geometric shapes by the time they reach 4th and 5th grade. The study of triangles, called Trigonometry, has been around for almost 2000 years. The earliest known study of triangles can be traced to the Egyptian and Babylonian civilizations in the 2nd millennium BC. Triangles are one of the basic shapes of geometry and are an important part of geometry learning. Shape games for kids are a great way to set a solid foundation for geometry learning. Help your child learn to identify and practice classifying triangles using math worksheets for kids like the classifying triangles worksheet.

A Triangle is a closed, 2-dimensional shape that has three sides, three corners and three angles. It is formed when three segments join three noncollinear points. Each segment of the triangle is called a side and the point where two segments meet is called a vertex. The three angles of a triangle always add up to 180^o. But not all triangles are the same, they come in different shapes and sizes. Use the classifying triangles worksheet to help your child understand how to classify triangles based on their angles and sides.

In this article, explore:

• Classifying Triangles Worksheet by Side Lengths
• Classifying Triangles by Angles Worksheet

Classifying Triangles Worksheet

Like other polygons, not all triangles are of the same shape and size. Triangles are classified based on the length of the sides, the measure of the interior angles and both the sides and angles they have. Learn how to classify triangles easily and practice them using the classifying triangles worksheet given below. These worksheets for kids will help them learn to classify triangles based on their side lengths, their angles and both sides and angles.

Classifying Triangles Worksheet by Side Lengths

Some triangles are classified according to the length of each side. Based on this, triangles can be classified into equilateral triangles, isosceles triangles and scalene triangles. Practice classifying triangles based on the side lengths using this classifying triangles worksheet.

Classifying Triangles by Angles Worksheet

Other than the side lengths, triangles can also be categorized based on the measure of the angles inside the triangle. Triangles classified based on their interior angles are of three types, right triangle, acute triangle and obtuse triangle. Help your child learn to identify and label triangles based on their angles using this classifying triangles worksheet.

Classifying Triangles Worksheet Based on Angles: With Angle Measures

How Are Triangles Classified?

Before you hand out a classifying triangles worksheet to your kids, helps them revise their lessons on classifying triangles. Triangles are everywhere around us. You can see them in flags, in musical instruments, in signboards, etc. Learning the properties of a triangle and classifying them is a crucial part of geometry lessons for kids in 4th and 5th grade. Triangles can be classified based on the length of the sides, their interior angles and both the measure of the sides and angles. 

Classifying Triangles Based On Sides

Based on sides, triangles can be divided into three types: equilateral triangle, isosceles triangle and scalene triangle.

1. Equilateral Triangle: An equilateral triangle is a triangle that has three equal or congruent sides. It also has 3 congruent angles, each of the angles measures 60^o.
2. Isosceles Triangle: A triangle, which has two sides of the same length is called an isosceles triangle.
3. Scalene Triangle: A triangle in which all three sides have different measures of length is called a scalene triangle. It does not have any congruent sides.

Classifying Triangles Based On Angles

Based on angles, triangles can be divided into three types: right triangle, acute triangle and obtuse triangle.

1. Right Triangle: A triangle with two acute angles and one right angle is called a right triangle.
2. Acute Triangle: A triangle in which all the interior angles are less than 90^o is called an acute triangle. 
3. Obtuse Triangle: A triangle with one obtuse angle and two acute angles is called an obtuse triangle.

Classifying Triangles Based On Sides And Angles

Based on both the sides and angles, triangles can be divided into 7 types. They are, acute equilateral triangle, obtuse scalene triangle, right isosceles triangle, right scalene triangle, acute scalene triangle, acute isosceles triangle and obtuse isosceles triangle.

1. Acute Equilateral Triangle: This triangle has 3 equal sides and 3 angles that are less than 90^o.
2. Obtuse Scalene Triangle: A triangle with unequal side lengths and one obtuse angle.
3. Right Isosceles Triangle: A triangle with two equal sides and one right angle. 
4. Right Scalene Triangle: A triangle with one right angle and 3 unequal sides.
5. Acute Scalene Triangle: A triangle with 3 unequal sides and 3 unequal acute angles.
6. Acute Isosceles Triangle: A triangle with two equal sides and two equal acute angles.
7. Obtuse Isosceles Triangle: A triangle with two equal sides and one obtuse angle.

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Frequently Asked Questions on Classifying Triangles Worksheet