Mathelp
  • Home
  • Algebra
    • Basic Concepts
    • Equations
  • Geometry
    • Angles
    • Triangles
  • Science
    • Biology
  • Problem Solving
  • Biographies
    • Mathematicians
No Result
View All Result
Mathelp.org
  • Home
  • Algebra
    • Basic Concepts
    • Equations
  • Geometry
    • Angles
    • Triangles
  • Science
    • Biology
  • Problem Solving
  • Biographies
    • Mathematicians
No Result
View All Result
Mathelp.org
No Result
View All Result
Home Geometry Angles

Angles: Definition, Elements and Examples

Learn what an angle is and how to measure it with the protractor.

Share on FacebookShare on Twitter

Angle

Definition:

An angle is a flat geometric figure formed by two rays having the same origin. These rays are called the sides of the angle and the common point is known as the vertex of the angle.

The main characteristic of an angle is its «opening«, that is, the way in which its sides are separated.

Look at the figure of the angle:

Angle

Angle Elements:

  • Sides: OA and OB
  • Vertex: «O»
  • Notation: Angle AOB = ∠AOB
  • AOB Angle Measurement: m∠AOB

⇒ m∠AOB = α

Note:

Every time we turn an object we are turning an angle, for example: when we open a window or door, when we turn the head from left to right, or in the clock we can appreciate the angles that make the hands.
Practically the angle is in everything that surrounds us.

Measurement of an Angle

We call the measurement of an angle the measurement of the amplitude of an angle. In Geometry we will represent the angle in sexagesimal degrees (°).

To measure an angle, we use the protractor, which is an instrument with which we can easily measure angles.

With the following figure we see the steps to measure an angle with the protractor.

Measurement of an Angle
Measuring angles using a protractor

Step 1 – We make the vertex of the angle to be measured coincide with the center «O».

Step 2 – Identify one side of the angle, let’s see the side: OA.

Step 3 – The other side of the angle points to the protractor. We can measure any angle, Examples:

i) m∠AOB = 40°
ii) m∠AOC = 90°
iii) m∠AOD= 123°
iv) m∠AOE = 155°

Important:

In the figure we can also see other measures of angles as:

  • m∠BOC = 50°
  • m∠COD = 33°
  • m∠BOE = 115°

In the types of angles, according to the measure, an angle can be: acute, right, obtuse.

Tags: AnglesTriangles

Related Posts

Obtuse Angle

Angle Obtuse: What is an obtuse angle?, Examples

Geometric-Figures

Geometric Figures: Definition and Examples of Flat and Solid Figures

Acute Angle: Definition and Examples

Deja una respuesta Cancelar la respuesta

Tu dirección de correo electrónico no será publicada. Los campos obligatorios están marcados con *

  • Privacy and Cookie Policy
  • Terms of use
Spanish version:Ciencia Matemática

© 2019 - 2020 Mathelp.org - All Rights Reserved.

No Result
View All Result
  • Home
  • Algebra
    • Basic Concepts
    • Equations
  • Geometry
    • Angles
    • Triangles
  • Science
    • Biology
  • Problem Solving
  • Biographies
    • Mathematicians

© 2019 - 2020 Mathelp.org - All Rights Reserved.

This website uses cookies. By continuing to use this website you are giving consent to cookies being used. Visit our Privacy and Cookie Policy.