A rhombus has diagonals 24 cm and 10 cm. Find the area (in sq cm) and the perimeter (in cm) of the rhombus, respectively, using standard rhombus diagonal properties.

Aptitude Area Difficulty: Medium
Choose an option
  • A
    Area 130 sq cm, Perimeter 50 cm
  • B
    Area 120 sq cm, Perimeter 52 cm
  • C
    Area 240 sq cm, Perimeter 52 cm
  • D
    Area 120 sq cm, Perimeter 48 cm
  • E
    Area 110 sq cm, Perimeter 56 cm

Answer

Correct Answer: Area 120 sq cm, Perimeter 52 cm

Explanation

Introduction / Context: This problem checks two core rhombus facts: (1) Area can be found directly from diagonals using Area = (d1*d2)/2, and (2) diagonals bisect each other at right angles, allowing side length to be found by the Pythagoras theorem using half-diagonals. Once the side is known, perimeter is 4 times the side. The main goal is to produce the correct ordered pair: (area, perimeter).

Given Data / Assumptions:

  • d1 = 24 cm
  • d2 = 10 cm
  • Area = (d1*d2)/2
  • Half diagonals: 12 cm and 5 cm
  • Side s = sqrt(12^2 + 5^2)

Concept / Approach: Compute area using diagonals formula. Compute side using right triangle formed by half diagonals. Then perimeter = 4*s. Keep units consistent (sq cm for area, cm for perimeter).

Step-by-Step Solution:Area = (d1*d2)/2 = (24*10)/2 = 240/2 = 120 sq cmHalf diagonals are 12 cm and 5 cmSide s = sqrt(12^2 + 5^2) = sqrt(144 + 25) = sqrt(169) = 13 cmPerimeter = 4*s = 4*13 = 52 cm

Verification / Alternative check: Since 12-5-13 is an exact Pythagorean triple, side = 13 is exact. Also area calculation is direct and exact. Therefore the ordered result (120, 52) is consistent and does not require rounding.

Why Other Options Are Wrong: Area 240 doubles the correct area because the division by 2 was missed. Perimeter 48 or 50 uses an incorrect side length due to not halving diagonals or incorrect square root. Area 110 or 130 indicates arithmetic mistakes in 24*10/2.

Common Pitfalls: Forgetting Area = (d1*d2)/2. Not halving diagonals before Pythagoras. Mixing up units (writing cm for area). Giving only one value when the question asks for both in order.

Final Answer: Area 120 sq cm, Perimeter 52 cm

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