Let's do this question, find the value of B. over here, this Angliss three B and we need to find the
value of B, all right.
Was the video give it a try and then let's do it together.
All right.
We are back in this picture.
You can see that angle C or B is equal to angle B or Q, why is that so?
And you remember why that is so.
Yes, because these two angles are vertically opposite angles.
Right.
And vertically opposite angles are equal to each other.
Therefore, Angle B or Q is equal to a hundred degree.
Now these three angles, if we add them right, we should get 180 degrees because they form a straight
angle.
Right.
Because a B is a straight line and we remember a straight angle is equal to 180 degrees.
Therefore angle B or A plus angle B or Q plus angle Q or B is equal to 180 degrees.
All right.
Now B or is to any degree B or Q is hundred degree and Q or B is equal to three B, therefore three
B is equal to 180 minus 120, which is equal to 60 degrees.
Or you get B's equal to 20 degrees.