Let's do this question in the following figure, Abbi's parallel to D.C. and aid is equal to B.C. Find
the value of X, so this is an isosceles tropism.
Pause the video, give it a try and then let's do it together.
All right.
We back.
I hope you have given it a try.
We are asked to find X in the middle over here.
We know that these two sides are equal.
So this is also 10 centimeters right now.
I can also find that this angle is 120 degrees because these two sides are parallel and this angle and
this angle have to be supplementary.
That gives me this angle, 180 minus 60, which is equal to 120 degrees.
All right.
Now let's proceed.
In the case of an isolationist tropism, you will find that this angle and this angle also will be equal.
So this angle over here is also 60 degrees.
Now, let me draw the such that D.C. is parallel to S.B.
So this line is parallel to this line.
Now, over here, you can see that DEA is splitting the 120 degree angle into two.
Let me mark this as angle one and let this be angle to.
All right.
Now you can see that angle one is equal to angle B, which is equal to 60 degrees, because now the
C, B, this shape over here, or B, C, D, E, the same is a parallel gram.
Right.
Because initially we knew that this side is parallel to the side and reconstructed the such that the
is parallel to c.B.
So we have a program over here.
Therefore opposite angles of a program are equal.
Therefore angle one over here is equal to 60 degree.
Angle two will be 120 minus angle one.
Right.
So that's one twenty minus sixty which gives you sixty over here.
So you have this angle of 60 and this angle at 60.
Therefore this angle also is 60.
That's 180, minus 60, minus 60.
So you'll get 60 over here also.
Therefore, Triangle 80 is an equilateral triangle right now.
Hence because the sides of any quadrangle are equal and it is given that it is equal to 10 centimeter,
therefore it also will be equal to 10 centimeters.
So we know it is equal to 10 centimeter.
All right.
Now, Ebbe will be equal to 20 centimeter because B, C, D, E is a program.
So this is a parallelogram.
We have seen that over here and we know opposite sides of a program are equal and ebb's equal to twenty
centimeter.
All right.
And over here, you can see X is equal to 80 plus Ebbie.
That's equal to 10 plus 20.
And hence the measurement of X is equal to 30 centimeters.
And that is your answer.