Perimeter comparison for equal areas:\nA square and a (non-square) rectangle have equal areas, with perimeters p and q respectively. Determine the correct relation between p and q.

Difficulty: Medium

Correct Answer: p < q

Explanation:


Introduction / Context:
(Recovery–First applied) The square minimizes perimeter for a given area among all rectangles. For equal areas, a non-square rectangle must have strictly larger perimeter than the square. We repair options to reflect the correct inequality, choosing the strict form when the rectangle is not a square.


Given Data / Assumptions:

  • Square area = Rectangle area.
  • Rectangle is not a square (otherwise perimeters would be equal).


Concept / Approach:
For fixed area A, by AM–GM (or calculus), the rectangle with minimum perimeter is the square. Thus p (square) is minimal, and any non-square rectangle has q > p.


Step-by-Step Solution (idea):

Let the rectangle have sides x and A/x. Perimeter = 2(x + A/x) ≥ 4√A with equality at x = √A (i.e., square).Hence for a non-square rectangle, 2(x + A/x) > 4√A, so q > p.


Verification / Alternative check:
Pick A = 100. Square 10×10 has p = 40. Rectangle 5×20 has q = 50 > 40.


Why Other Options Are Wrong:
p > q contradicts the extremal property; p = q holds only if the rectangle is also a square; “none” is unnecessary since the strict inequality is known.


Common Pitfalls:
Assuming equal areas imply equal perimeters; perimeter depends on side distribution, not area alone.


Final Answer:
p < q

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