InterviewSolution
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The area of a rhombus is 216 cm2 and one of the diagonals is 18 cm. Find the perimeter of the rhombus.1. 15 cm2. 24 cm3. 60 cm4. 48 cm |
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Answer» Correct Answer - Option 3 : 60 cm Given: Area of the rhombus is 216 cm2 Length of a diagonal = 18 cm Concept used: The two diagonals bisect each other at 90° in a rhombus. Formula used: Area of rhombus = (1/2) × Product of the two diagonals Perimeter = 4 × (Side of the rhombus) Calculations: Let the second diagonal of the rhombus be x and the side of the rhombus be a Area of rhombus = (1/2) × 18 × x ⇒ 216 = (1/2) × 18x ⇒ 18x = 432 ⇒ x = 24 cm If the two diagonals of rhombus ABCD intersect at O then, ⇒ AO2 + BO2 = AB2 ⇒ (18/2)2 + (24/2)2 = a2 ⇒ 81 + 144 = a2 ⇒ a2 = 225 ⇒ a = 15 cm Perimeter of the rhombus = 4a ⇒ 4 × 15 ⇒ 60 cm ∴ The perimeter of the rhombus is 60 cm. |
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