In this video, we challenge you to find the missing area of a rectangle using the information shown in the diagram. Test your geometry skills, logical reasoning, and understanding of area calculations.
Watch until the end to understand how to approach this maths problem, then comment with your answer before checking the solution!
Topics covered:
* Tricky maths questions and puzzles * Rectangle area calculations * Geometry challenges * Finding missing values * Mathematical reasoning and problem-solving
Think you know the answer? Leave it in the comments!
Follow for more maths puzzles, brain teasers, geometry questions, and educational challenges.
Let's find the area of the shaded portion or area of the space.
Welcome back to my channel.
This is a rectangle.
Okay, this is a square.
Sorry.
And this particular one, we're also looking for its area is a square.
Now, if this is a square, that implies,
so I'll write this, that ABCD is a square.
All right.
now if AB is equal to BC is equal to DC
is equal to AD let's call this x okay
so let AD be equal
to x it also means that AB is x as well right
this is also x then BC is also x and DC is also x
Now, if we look at this question,
we are asked to find the area of this portion.
Now, because this is a square as well,
now, let's call this MN rather.
If we say that NB is equal to y,
then let every other part of this square become y.
So, this is y, right?
it means that from B to let's call this P from B
to P is also y and from P to M let's call this
portion M is also y therefore from here to here
is y okay now let's try to get these parts the
parts of this particular square AN will be the whole of x minus
y right so we have AN is x
minus y and the same thing PC will be what
the whole of this is x minus y x minus y please
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comment section all right now moving forward remember
that a and D whatever
that is here right this is a rectangle now let's call
this X okay that's X
let's call DC okay so a and DC is a rectangle
and area area of a rectangle
is equal to the length times
the breadth, okay?
So that means that x times x minus y will give us 15
because the area here is 15.
So this implies that x multiplied by x minus
y is equal to 15.
Let's call this equation 1.
Now, similarly, for this side,
we have y multiplied by x minus y is 9.
So, y multiplied by x minus y is 9.
Now, let's call this equation 2.
I think this is enough.
Yes.
Now, let's divide equation 1 by equation 2.
So, equation 1 divided by 2.
this implies we have x brackets x minus y over
y brackets x minus y and this will be equal to 15
divided by 9 now they share something in common x minus
y x minus y so this implies that x divided
by y is equal to 15 divided by 9 now if we make x
the subject of the formula let's cross multiply
we have 9x is equal to 15
y okay now let's make um x the subject
of the formula or let's make y
the subject of the formula anyone so but let's go with x
so dividing both sides by 9 we will have
that x is equal to 15 over 9, 3 go into this 15
so we are going to have 5 over 3 y
5 over 3 y so this is our x
and it is very important to write it down that x is equal to 5
over 3 y now we are going to rewrite
this particular equation here okay let's do that
before i erase it so we have x multiplied by x minus
y is 15 and x and y multiplied by x minus y
is 9 so i can now erase
everything i have space
all right we have 5 over 3
y as our x so i want
to substitute it into the second equation i don't want to have too much
and this thing to solve
too much fractions to solve.
So, substituting it into equation 2, we have y multiplied by,
so we're going to replace x with 5 over 3y minus
y is equal to 9. So, let's solve what we have
inside the brackets. We have y brackets, 5y over 3 minus y over 1.
Let's write it like this,
and this is 9.
Okay, so we have y into, the LCM of 3 and 1 is 3, right?
So we can write this as
5y over 3 minus, we multiply this side by 3.
And if we do that, we have 3y over 3 is equal to 9.
So, now we have y brackets,
5y minus 3y, all divided by 3,
is equal to 9.
So, y brackets, 5y minus
3y is 2y over 3, is equal to 9.
Now, if we solve for that, if you have not subscribed
to the channel, you are missing something.
So, I would like you to subscribe to the channel.
Okay. All right.
So now we have y times 2y is 2y
squared divided by 3 is equal to 9.
Okay. If we cross multiply,
we have 2y squared is equal to 3 times 9 is 27.
So we divide both sides by 2 to get y squared.
So, we have y squared is equal to,
27 is 13.5 then.
So, 27 will be 13.5, yeah, 13.5.
Now, I'm going to stop here.
Do you know why?
We are asked to find the area of this square.
And area of a square is length squared, right?
And the length of this portion is y.
Meaning that the area, area of this portion is y squared.
and we have already found it from here
that y squared is equal to 13.5 therefore the area
is 13.5 units squared thank you
so much for watching see you in my next video