Difficulty: Medium
Correct Answer: 34 cm
Explanation:
Introduction / Context:Let the square side be x. The rectangle’s dimensions become (x + 5) and (x − 3). Equal areas give an equation to solve for x, and hence perimeter.
Given Data / Assumptions:
Concept / Approach:Set x^2 = (x + 5)(x − 3) and solve for x; compute perimeter P = 2[(x + 5) + (x − 3)].
Step-by-Step Solution:
x^2 = x^2 + 2x − 15 ⇒ 2x − 15 = 0 ⇒ x = 7.5 cm.Rectangle L = 12.5 cm, B = 4.5 cm.Perimeter = 2(12.5 + 4.5) = 2 * 17 = 34 cm.Verification / Alternative check:Area check: square 7.5^2 = 56.25; rectangle 12.5 * 4.5 = 56.25 ✔️
Why Other Options Are Wrong:15, 18, 26 come from miscomputing x or forgetting to double for perimeter.
Common Pitfalls:Sign errors when expanding (x + 5)(x − 3); arithmetic errors with decimals.
Final Answer:34 cm
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