Understanding angles using a protractor

Understanding angles using a protractor

Don't know what a protractor looks like?

Isn't it semi-circular!

A half circle means you close your eyes and say 180⁰!

The angle measurements in the protractor are only up to 180⁰. That is, up to the straight angle.

If half of the protractor is 90⁰? That means half of the protractor is a right angle.

Now try connecting the two protractors. Will it come full circle? How much angle does it come to? 180⁰ + 180⁰ = 360⁰ itself? Yes full circle means 360⁰ itself?

Have you seen, How many things can we infer without pointing a protractor in your eye? That is the specialty of mathematics. If you're good at math, you can infer things very accurately and very quickly without seeing them.

This is how the diameter of the earth, the circumference and the distance of the planets were calculated. That is, they have predicted without measuring with instruments.

This is how in engineering the structure or construction needs to be presupposed and drawn. That is why mathematics plays an important role in engineering.

Only in engineering? Mathematics helps us to make assumptions in all fields. How much does a doctor infer from blood pressure levels? What is blood pressure level? Is it the numbers? That's why I often say that math is all about numbers and become good at those numbers.

Ah, did you see that we left the angle to wonder at the math? We didn't give up. It's something you know. However, with that said, this topic will be complete.

Angles between 1⁰ and 89⁰ are called acute angles. i.e. the angles between the zero angle and the right angle.

Angles between 91⁰ and 179⁰ are called obtuse angles. i.e. the angles between a right angle and a straight angle.

Angles from 181⁰ to 359⁰ are called reflex angles. i.e. the angles between a straight angle and a full angle.

Let us tabulate this.

S.No.	Angle size	Name of the angle
1.	00	Zero angle
2.	From 10 to 890	Acute angle
3.	900	Right angle
4.	From 910 to 1790	Obtuse angle
5.	1800	Straight angle
6.	From 1810 to 3590	Reflex angle
7.	3600	Complete / Full angle

 

What do you mean by the names of so many angles? Don't we have many friends? Doesn't everyone have a name?

For those of you who are interested in calculations, numbers are your friends. Friends of your numbers in the Angular world have these names. Do you like having extra friends? Will we bother to remember their names?

What's next you ask?

We can complete this simple introduction to mathematics by knowing a little about graphs.

That is what we are going to see next.

*****