Difficulty: Hard
Correct Answer: 34 cm
Explanation:
Introduction / Context:
This problem combines algebra with mensuration. You are told a square and a rectangle have equal area, but the rectangle’s sides depend on the square’s side. The correct method is to let the square side be s, write the rectangle dimensions as (s + 5) and (s - 3), equate areas, solve for s, then compute the rectangle perimeter 2 * (l + b).
Given Data / Assumptions:
Concept / Approach:
Form an equation using equal areas, solve for s, then substitute to find rectangle sides and perimeter. Ensure the breadth stays positive (s must be greater than 3).
Step-by-Step Solution:
Verification / Alternative check:
Square area = 7.5^2 = 56.25. Rectangle area = 12.5 * 4.5 = 56.25. Areas match, so the perimeter computed from these rectangle sides is consistent.
Why Other Options Are Wrong:
Common Pitfalls:
Students often forget to expand correctly, or incorrectly cancel terms. Another mistake is using perimeter of square instead of rectangle. Also, do not assume s is an integer; s can be fractional as seen here.
Final Answer:
34 cm
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