The perimeter of a rectangle is 44 centimetres and its breadth is 10 centimetres. Find the area of the rectangle in square centimetres.

Difficulty: Easy

Correct Answer: 120 square centimetres

Explanation:


Introduction / Context:
This problem checks basic understanding of rectangle properties and the use of perimeter and area formulas. Such questions are fundamental in quantitative aptitude and help you practise extracting unknown dimensions from given information and then using them to compute area.


Given Data / Assumptions:

  • The figure is a rectangle.
  • Perimeter of the rectangle = 44 cm.
  • Breadth (one side) = 10 cm.
  • We are asked to find the area in square centimetres.
  • All angles in a rectangle are right angles and opposite sides are equal.


Concept / Approach:
For a rectangle:
Perimeter = 2 * (length + breadth).
Area = length * breadth.
We first use the perimeter to find the missing side, which is the length, and then substitute into the area formula. This is a straightforward two step application of standard formulas.


Step-by-Step Solution:
Step 1: Let length = L cm and breadth = B = 10 cm. Step 2: Perimeter = 2 * (L + B) = 44. Step 3: So, 2 * (L + 10) = 44. Step 4: Divide both sides by 2: L + 10 = 22. Step 5: Hence, L = 22 - 10 = 12 cm. Step 6: Area of rectangle = length * breadth = 12 * 10. Step 7: Area = 120 square centimetres.


Verification / Alternative check:
Check the perimeter using the found dimensions:
2 * (12 + 10) = 2 * 22 = 44 cm, which matches the given perimeter. This confirms that length = 12 cm and the area value 120 square centimetres is consistent.


Why Other Options Are Wrong:
60 square centimetres: This could occur if a side was miscalculated or halved incorrectly.
180 square centimetres: This would imply dimensions like 18 by 10, giving a larger perimeter than 44 cm.
200 square centimetres: Requires a different length, inconsistent with the given perimeter.
240 square centimetres: Would correspond to 24 by 10 and a perimeter of 68 cm, which is not correct.


Common Pitfalls:
Learners often confuse perimeter and area formulas or forget to divide by 2 when using the perimeter equation. Another common mistake is using 44 directly as one of the sides. Always remember that perimeter for a rectangle involves the sum of all sides, not the product, and that area is obtained only after correctly finding both length and breadth.


Final Answer:
The area of the rectangle is 120 square centimetres.

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