Question

Q7. Construct angle 120°.​

Answer 1

Step-by-step explanation:

Question:

❥ Construct angle 120°.

Understanding -

➸ So, question says that we need to construct an angle of 120°.

➸ We can construct only those angle who are a multiple of 15.

➸Like, 30,45,60,75,90 etc...

➸ So, first we need to check is 120 divisible by 15.

➸ 120/15 = 8.

➸ Hence, it is divisible.

Solution :

Step 1 =

First draw a random line .

Step 2 =

Then, from the corner of the line draw an arc of any measure.

Step 3 =

Using the same arc from the corner of the drawn 180 degree arc draw a line. ( Now it depends from which side do you draw from one side it may be 60 degree and one side it would be directly 120 degree)

Step 4 =

Now if it's drawn 60 degree then from that point using the same arc draw another one.

Step 5 =

Now, we have the arc for 120 degree from that we can draw a line.

Name the line AB or PQ or anything.

We have constructed an angle of 120°.

Points to be remembered -

➸Make sure that your pencil is small not to big otherwise might be you face trouble while constructing.

➸Your pencil ✏ shouldn't be blunt.

➸Make the arcs accurate.

➸Don't change the arc otherwise maybe your angle may differ.

More information :

❥There are some angles which cannot be constructed using compass and scale. For them we directly use protector.

❥ What is an Obtuse angle?

Angle which measure measures more than 90 degree and less than 180 degree is called an obtuse angle. Example - 111 degree , 120 degre, 160 degree etc..

❥What is an Acute angle?

Angle which measures less than 90 degree is known as an acute angle. Example - 5 degree,15 degree ,60 degree etc..

For reference,

Picture is also attached.

Thank you!!!

Hope it helps you!!