Angles – Parts and Types

This geometry lesson is designed for 6 to 12-year-old children. This video lesson guides the children about different parts and types of angles. The practical examples using real-life objects, like a laptop, a frame, and others, help the child in getting a better understanding of the concept.

Let us first understand angles and their types.

What are Angles? 

The word angle came from the Latin word “Angulus” which means corner. Angles are geometric shapes formed by joining two rays at their ends. In other words, when two rays (arms) are joined together at a single point, they create an angle. It is represented by the symbol ‘∠‘ and measured in degrees’ °.’

What are the Parts of an Angle?

An angle has three parts

• Vertex- The common point where two sides of an angle meet are known as the vertex. 
• Arms– The two sides of the angle, joined by the vertex, are called the Arms of an angle.
• Amplitude – The space between the two arms is known as amplitude.

What are Different Types of Angles?

Angles are classified according to the measure of the angle. 

1. Acute angle
2. Right angle
3. Obtuse angle
4. Straight angle
5. Reflex angle

Let us learn about them one by one in detail.

• Acute Angle

Angles that are less than 90° are called acute angles. Some examples of acute angles are 20°,30°,45°,60° and so on. 

• Right Angle

If the angle formed by two rays is exactly 90°, it is referred to as a right angle or a 90° angle. Generally, it is formed when two lines are perpendicular to one another.

• Obtuse Angle

Any angle greater than 90° but less than 180° is known as an obtuse angle. Obtuse angles range from 90° to 180°. Some examples of obtuse angles are 110°, 125°, 140°, and 165°. It can also be found by the below formula:

Obtuse Angle Measure = (180 – acute angle measure)

• Straight Angle

An angle that is 180° in length is known as a straight angle. In its simplest form, a straight angle is a straight line with an angle of 180°. A straight angle is a combination of obtuse and acute angles that make up a straight line. It can also be formed by combining two adjacent right angles. In other words, two right angles make up a straight angle.

• Reflex Angle

The reflex angle is an angle greater than 180 degrees and less than 360 degrees. Examples of reflex angles are 215°, 260°, 325°, etc.

What are the Uses of Angles in Daily Life?

These different types of angles are found in nature, and each one plays a key role in our daily lives. Children can discover angles in every object and place around them. Let us understand how?

• Architects and engineers use angles to design houses, machines, buildings, roads, and bridges.
• Angles help athletes perform better. In every sport, angles play a vital role. For example, in cricket, the batsman turns the bat at a certain angle to hit the ball to move it toward the boundary.
• Carpenters use angles to fabricate furniture such as sofas, tables, chairs, pails, etc. 
• Artists use angles to draw portraits and paintings. 
• Fashion designers use angles to design outfits. 
• In Geography, any location is measured by latitudes and longitudes using angles subtended at the center of the Earth.
• In astronomy, the rotation of the Earth, other planets, and other celestial bodies is also measured by angles. And so on

Watch the video to learn more about angles and encourage the child to find angles in their surroundings, like houses, supermarkets, schools, etc.

Related Video Resources

• Classification of triangles
• Types of lines

To view more math video resources, click here.

Video Created by: Justine McNeilly

FAQs

• What is an angle?

An angle is a geometric figure formed by two rays that share a common endpoint, known as the vertex.

• How are angles measured?

Angles are typically measured in degrees. A full rotation is equal to 360 degrees, and a straight angle is equal to 180 degrees. Angles can also be measured in radians, which is a unit of measurement based on the radius of a circle.

• What is a right angle?

A right angle is an angle that measures exactly 90 degrees. It is typically represented by a small square in the corner of the angle.

• What is an acute angle?

An acute angle is an angle that measures less than 90 degrees.

• Is the obtuse angle and reflex angle the same?

No, an obtuse angle and a reflex angle are not the same. An obtuse angle is an angle that measures between 90 and 180 degrees, while a reflex angle is an angle that measures between 180 and 360 degrees.