A rectangle $PQRS$ has dimensions 20 cm by 10 cm. A square of side $x$ cm is cut from each of two corners of the rectangle. The area of the remaining shaded region is 484 $cm^2$. We need to find the value of $x$.

GeometryAreaRectangleSquareAlgebraic Equations
2025/4/20

1. Problem Description

A rectangle PQRSPQRS has dimensions 20 cm by 10 cm. A square of side xx cm is cut from each of two corners of the rectangle. The area of the remaining shaded region is 484 cm2cm^2. We need to find the value of xx.

2. Solution Steps

The area of the rectangle PQRSPQRS is given by:
Arearectangle=length×widthArea_{rectangle} = length \times width
Arearectangle=20×10=200Area_{rectangle} = 20 \times 10 = 200 cm2cm^2
The area of each square that is cut out is:
Areasquare=side×sideArea_{square} = side \times side
Areasquare=x2Area_{square} = x^2 cm2cm^2
Since there are two squares, the total area of the two squares is 2x22x^2 cm2cm^2.
The area of the shaded region is the area of the rectangle minus the area of the two squares.
Areashaded=Arearectangle2×AreasquareArea_{shaded} = Area_{rectangle} - 2 \times Area_{square}
We are given that the area of the shaded region is 484 cm2cm^2. Therefore,
484=2002x2484 = 200 - 2x^2
This equation is incorrect.
The problem states a rectangle PQRSPQRS from which a square of side xx has been cut.
The diagram shows TWO squares cut from the corners. So the correct equation is:
Areashaded=Arearectangle2AreasquareArea_{shaded} = Area_{rectangle} - 2 Area_{square}
484=20×102x2484 = 20 \times 10 - 2x^2
484=2002x2484 = 200 - 2x^2
2x2=2004842x^2 = 200 - 484
2x2=2842x^2 = -284
This implies that x2x^2 would be negative, which is not possible.
Let's examine the problem description and the diagram again.
Rectangle PQRSPQRS has length 20 cm and width 10 cm, area = 200 cm2cm^2.
Two squares of side xx cm are cut. Thus the area of the two squares is 2x22x^2.
The area of the shaded region is given as 184 cm2cm^2. Thus:
2002x2=184200 - 2x^2 = 184
2x2=200184=162x^2 = 200 - 184 = 16
x2=8x^2 = 8
x=8=22x = \sqrt{8} = 2\sqrt{2}
The original text states "The area of the shaded portion is 484 cm2cm^2". The diagram looks as if the shaded region is slightly smaller than the unshaded. Therefore, the number 484 may be a misprint. However, the problem text is important, so we must go with it. Let's try again.
2002x2=484200 - 2x^2 = 484 is not correct. The error is that the squares have been added instead of subtracted.
Looking at the diagram, it looks as if two rectangles are subtracted. If 10 cm and 10 cm are deducted from 20 cm and the shaded area is 184 cm2cm^2. This seems plausible.
Let's assume that the correct area of the shaded portion is
1
8

4. $200 - 2x^2 = 184$

2x2=162x^2 = 16
x2=8x^2 = 8
x=8=22x = \sqrt{8} = 2\sqrt{2}
However, since we are asked to solve the problem as it is, the calculation with 484 is important:
2002x2=484200 - 2x^2 = 484
2x2=284-2x^2 = 284
2x2=2842x^2 = -284
Since a negative value does not make sense, there might be a typo in the question, but to answer the question with the information as is.
Area of rectangle - 2 * area of squares = area of shaded region
20 * 10 - 2 * x * x = 484
200 - 2x^2 = 484
-2x^2 = 284
x^2 = -142
x = sqrt(-142)
x does not exist, since there is no real number xx such that x2=142x^2 = -142.
Since 2x22x^2 cannot be greater than 200, it must be a misprint in the problem
If we assume that the total area of shaded region is 184:
2002x2=184200 - 2x^2 = 184
2x2=162x^2 = 16
x2=8x^2 = 8
x=8=222.83x = \sqrt{8} = 2 \sqrt{2} \approx 2.83

3. Final Answer

There is no real solution for xx given the problem. If the area of the shaded region was 184 cm2cm^2 instead of 484 cm2cm^2, then x=22x = 2\sqrt{2} cm. Since the problem says the area is 484, the area of the squares would be negative. There seems to be an error in the question, therefore, it is not solvable.
Since we are asked to find the value of xx, and given the question, we can conclude that the problem has no solution.
x=142x = \sqrt{-142} (This is not a real solution, but we follow the directions given). Since the value of xx is non-real, we cannot provide a final answer for this problem.

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