Let's do this question, find this ratio that is 80 of ABCDE to the area of Triangle Deep Cube, that
is this triangle over here to the area of Triangle dequeue.
That's this triangle over here.
Alright, pause the video, give it a try and then let's do it together and do try to use graphical
division method to find this answer because it'll save you a lot of time.
All right.
We we're back.
I hope you've given it a try.
Let's do it together now.
Over here, you can see that it is 20 and DC is 20 centimeter.
And it's given that this angle is 90 degrees.
So ABCDE is a square.
Right.
And we know that area of a square is side square.
So area of ABCDE is 20 to 20.
That's four hundred.
All right.
Now let's drop it perpendicular from B, so Apison that means B also is equal to 10 or P is the midpoint
of Abe.
All right.
Now, let me drop it perpendicular from B to let me see at our.
All right.
Now you can see that B R has divided this square into two parts of equal area.
Remember that similar to the first problem we discussed in the introduction to graphical division.
All right.
So we have a party and BCR and each of these will be of equal area.
So you have two hundred over here and two hundred over here.
All right.
Now, let's see, Beardie.
There is a nine party over here.
This is a diagonal to A, B, R, B, right.
So this two hundred is divided into two by P.E.T..
Right.
You have triangle apre and triangle pedia and each of these will be of hundreds and hundreds centimetres
square each.
Right.
So let's write that over here.
You have a pretty standard annual periodical to handle, all right.
Now, over here, it's given that QCA right there for Cubie also will be 10.
That is.
Q is the midpoint of beseen now from Q Let's draw a perpendicular touching 80 at S right.
So over here you can see that esq, you see them will have an area of two hundred in a similar manner
that we saw over here.
And Kudi is a diagonal to skew.
Therefore the area of Triangle Deek you see will be half of two hundred that is handed over here.
Right.
All right, let's proceed.
Now you can see that or b, b, q that's all we BQ this is forming one by fourth of the area of the
square.
Can you see that.
Why is that.
So let's take any one over here.
For example, you take P r we have seen that BBC R is half of the area of the square and over here again
you divide it into two.
Right.
So this part will be half of half.
That is one by four of the area of the square will be P q OK, so the area of barbecue will be one by
four in the form that that's equal to a hundred.
All right.
Now P Q is a diagonal to be Q Right.
And hence P Q is dividing it into two equal areas.
Therefore the area of P, Q, B is half of hundert.
That is equal to 50.
Right.
So let's mark that over here.
Now let's try to find the answer.
What would be the area of deep.
Q That would be four hundred minus under plus 50 plus hundred.
Right.
So you just need to subtract these three from four hundred to get the deep.
Q All right, let's write that over here.
The area ODP, you will be four hundred minus hundred, minus hundred minus fifty and therefore the
required area or the required ratio over here will be one that is to 150 is two hundred or that is the
area of the square.
We have that over here.
150 is the area of deep.
Q When you do this you will get one fifty.
Right.
And the area of Triangle DC.
Q That would be a hundred.
Alright, so you can note over here that using graphical division method we were able to do this question
very fast.