What is an angle?

An angle is the figure formed by two halves starting from the same point. That common point is called the vertex, and each half-line is called the arm.

It is important to know that depending on the angle measurement, they will be classified in one way or another.

They are acute if they measure less than 90°, right if they measure exactly 90°, obtuse if they exceed 90° but are less than 180°, straight if they measure 180°, complete if they are 360º, and reflex if they are between 180° and 360°.

Here, I leave you a table that explains the classification of angles according to their measure:

How to measure an angle?

We use a protractor.
The centre of the protractor is placed on the vertex of the angle.
Align one side with 0°, and measure to the other side.

In order to understand it better, here I leave you a video in which it explains visually how to measure an angle at the same time that it remembers its classification. You just have to click on the image below!

Did you know...?

A triangle always adds up to 180° at its three inner angles.
The clock is an angle in motion: when it marks 3:00, the hands form a right angle (90°).
The corners of an A4 sheet are right angles.
The base of the Eiffel Tower opens at obtuse angles to be more stable.

Visual Resources:

Finally, I leave you a video that explains in an easy and simple way everything we have seen today.

Canva Presentation

Here I leave you a presentation of canva that I have designed so that you can review all the concepts. At the end of the theory I have added some activities for you to test your knowledge. Let’s go!

🎲Practice what you’ve learned!

Then I leave you an interactive game. I have also added a card in which you must complete with the name of each angle where you can check what you’ve learned today.

Interactive game: https://wordwall.net/resource/56043

Card to review: