The length of a rectangle is reduced by 20% and breadth is kept constant, and the new figure that is formed is a square. Consider the following statements: 1. The area of square is 25% less than the area of rectangle. 2. The perimeter of square is approximately 11% less than the perimeter of rectangle. 3. The diagonal of square is approximately 12% less than the diagonal of rectangle. Which of the statements given above is/are correct?
Aptitude
Area
Difficulty: Hard
Choose an option
-
A1 only
-
B1 and 2
-
C2 and 3
-
D1, 2 and 3
Answer
Correct Answer: 2 and 3
Explanation
### Concept & Shape Geometry Analysis
Compare derived dimensions of modified shapes by setting the new dimensions equal to establish the base ratio.
$$ Ratio = \frac{New - Old}{Old} \times 100 $$
### Step-by-Step Solution
* Initial parameters and variable relationships between the rectangle and square are established.
* Standard geometric formulas for area, perimeter, and diagonal are evaluated and compared.
* Final evaluation confirms Statements 2 and 3 perfectly match the computed variance.
### Exam Strategy & Shortcut
Assume $B = 8$, making initial $L = 10$. Original perimeter = 36, Square perimeter = 32. The drop is $4/36 = 11.11\%$. Skip calculating the area since option elimination heavily favors checking the perimeter first.
### Common Pitfall
Assuming length and breadth can be arbitrary numbers without establishing their rigid mathematical relationship dictated by the square formation constraint.
### Final Answer
Therefore, the correct answer is **2 and 3**.