The problem describes a rectangle $PQRS$ from which a square of side $x$ cm has been cut. The dimensions of the rectangle are 20 cm and 10 + 10 = 20 cm. The area of the shaded portion is 484 cm$^2$. We need to find the value of $x$.
2025/5/8
1. Problem Description
The problem describes a rectangle from which a square of side cm has been cut. The dimensions of the rectangle are 20 cm and 10 + 10 = 20 cm. The area of the shaded portion is 484 cm. We need to find the value of .
2. Solution Steps
First, we calculate the area of the rectangle .
Area of rectangle = length width = cm.
Next, we calculate the area of the square that was cut out.
Area of the square = side side = cm.
The area of the shaded region is the area of the rectangle minus the area of the square.
Area of shaded region = Area of rectangle - Area of square
Now, we solve for :
However, the diagram is incorrect. Assuming the width of the rectangle is 10 cm and the length is 20 cm, the area of the rectangle would be 20 * 10 = 200 cm. Then:
Area of shaded region = Area of rectangle - Area of square
is not correct.
Let's assume the area of the cut out is and the problem meant the area of the *uncut* portion. The area of the uncut portion is then the rectangle area minus the square's area.
Area of rectangle PQRS = .
Area of square =
Area of shaded region =
, which doesn't make sense.
Let's interpret the 10 cm + 10 cm as the length of the rectangle. So the rectangle is actually a square with sides 20 cm. The area of the rectangle PQRS is then .
Area of rectangle PQRS = .
Area of square = .
Area of shaded portion = Area of rectangle - Area of square
is not valid, as would be negative.
However, if the cut-out portion is not inside the rectangle, and the question says, the remaining region is 484, then:
If the full rectangle has length 20 cm and the width is cm, area is
4
0
0. If 10 cm is meant as the length, the area of the whole rectangle is $20 \times 10 = 200$. The question may intend us to cut out this square, and something strange happens and area of shaded region is 484 >
2
0
0.
We interpret that one side is 20 cm and the other is 10 cm and the small square with side x cm is removed.
The area of the uncut portion is .
which is wrong. negative.
Let us ASSUME that the total area of the rectangle is and area of the shaded area is still
4
8
4. Then $20 \times a - x^2 = 484$.
If length = 20 cm and width is 10 + 10 = 20 cm, the whole area is 400 cm. Then, if area of shaded part is 484, then the question has problems.
If the rectangle has width 10 cm and length 20 cm then the area of the rectangle is 200 cm. Let the small square have sides x. Then
which is not possible.
Let's assume that the sides are 20 and
2
0. $20 * 20 = 400$. We remove the square from it to leave
4
8
4. So $400 - x^2 = 484$ is incorrect.
If we interpret that after removing the cut out the area is still :
Let length of rectangle = 20 cm and width is .
Then area of rectangle = . is removed and remaining area is .
which is incorrect.
The area of the shaded region is 484 cm.
The area of the rectangle is 20 cm * 20 cm = 400 cm.
The area of the square is cm.
The area of the rectangle minus the area of the square equals the area of the shaded region: .
. Since cannot be negative, there is no real solution for .
Let's assume the area of rectangle is and is cut,
so .
, no solution.
3. Final Answer
There is no real solution for x.