Acute Angles & Right Angle

Lesson Objective

In this lesson, we will learn what are acute angles and right angle.

Study Tips

Tip #1

If an angle is greater than 0° and lesser than 90°, it is called an acute angle. Below are some examples:

Tip #2

Right angle is exactly equals to 90°.

The math videos below will explain more on this.

Math Video

Video on Acute Angles

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Video on Right Angle

Math Video Transcript

00:00:03.120
In this lesson, we will learn about acute angles.

00:00:08.100
Let's take a look at this angle.

00:00:11.140
Now, since this angle, is somewhere in between 0 degrees and 90 degrees, it is an angle.

00:00:19.140
Hence, we can say that an acu. angle, is always greater than 0 degrees, and lesser than 90 degrees.

00:00:29.010
Let's see some examples to understand this better.

00:00:33.130
Consider this angle of 80 degrees. Is this an acu. angle? Yes! it is.

00:00:45.120
How about this angle, of 35 degrees? Yes! It is an acu. angle.

00:00:54.140
Alright, take a close look at this angle. Is this an acu. angle?

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We know that, an acu. angle, is always greater than 0 degrees. This is true, for this angle.

00:01:11.020
Also, it is always lesser than 90 degrees. Again, this is also true, for this angle.

00:01:21.130
Yes, it is. 

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Next, how about this angle?

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Clearly, this angle is greater than 90 degrees.

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Hence, it is not.

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That is all for this lesson.

RIGHT ANGLE

00:00:04.020
In this lesson, we will learn about right angle.

00:00:08.080
By now, we should know that, acu. angles must be in between 0 degrees, and 90 degrees.

00:00:16.020
So, what happens if the angle is 90 degrees?

00:00:21.050
When the angle is 90 degrees, it will be called, right angle.

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Now, this angle is quite special. It has its own square symbol, to represent it.  

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To emphasize again, the right angle simply means that, the angle is 90 degrees.

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Now, let's see some examples on this.

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Is this a right angle? Yes! It is.

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How about this? Yes again.

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Next, is this a right angle? No, it is not.

00:01:12.030
That is all for this lesson. Try out the practice question to further your understanding.

Practice Questions & More

Multiple Choice Questions (MCQ)

Now, let's try some MCQ questions to understand this lesson better.

You can start by going through the series of questions on acute angles and right angle or pick your choice of question below.

Question 1 on identifying acute angles.
Question 2 on identifying right angles

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