Rectangle with given perimeter and offset length\nThe length of a rectangle is 10 cm more than its breadth. If the perimeter is 44 cm, find the length of the diagonal (in cm).

Difficulty: Medium

Correct Answer: 17.08 cm

Explanation:


Introduction / Context:
This problem blends linear relations (perimeter and difference between sides) with the Pythagorean theorem to determine the rectangle’s diagonal.


Given Data / Assumptions:

  • Perimeter P = 44 cm
  • Let breadth = b; length = b + 10
  • Diagonal d = sqrt(l^2 + b^2)


Concept / Approach:
Perimeter relation: 2(l + b) = 44 ⇒ l + b = 22. Combined with l = b + 10 gives a solvable linear pair for l and b. Then apply Pythagoras for the diagonal.


Step-by-Step Solution:

l + b = 22 and l = b + 10 ⇒ 2b + 10 = 22 ⇒ b = 6 cm, l = 16 cm d = sqrt(16^2 + 6^2) = sqrt(256 + 36) = sqrt(292) ≈ 17.088 cm Rounded to two decimals ⇒ 17.08 cm


Verification / Alternative check:
Perimeter check: 2(16 + 6) = 44 (correct). The diagonal magnitude is reasonable for these sides.


Why Other Options Are Wrong:
12.50 cm, 14.21 cm, and 15.98 cm are not the true space diagonal for sides 16 cm and 6 cm.


Common Pitfalls:
Mixing up perimeter with area or mistakenly using (l - b) instead of (l + b) to form equations will lead to incorrect side values.


Final Answer:
17.08 cm

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