What is the perimeter of a rhombus if the area of the rhombus is 840 cm2 and length of one of the diagonal is 2 cm more than the other diagonal?
What is the perimeter of a rhombus if the area of the rhombus is 840 cm2 and length of one of the diagonal is 2 cm more than the other diagonal? Correct Answer 116 cm
Suppose the length of a diagonal is ‘x’ cm then the length of other diagonal will be ‘x + 2’ cm;
We know that:
Area of a Rhombus = 1/2 × (Product of diagonals)
∴ 840 = 1/2 × x × (x + 2)
⇒ 1680 = x2 + 2x
⇒ x2 + 2x – 1680 = 0
⇒ (x – 40) (x + 42)
⇒ x = 40 or -42
∴ Length of a diagonal = 40 cm
Length of another diagonal = 40 + 2 = 42 cm
We know that the diagonals of a rhombus bisect each other at right angle.
∴ (Side)2 = (d12 + d22)/4
⇒ (Side)2 = (1600 + 1764)/4
⇒ (Side)2 = 841
⇒ Side = 29 cm
∴ Perimeter of a rhombus = 29 × 4 = 116 cm
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Feb 20, 2025