Find the perimeter of the rectangle, which has area of 20 Sq. cm and the diagonal of Sq. root of 41 cm.
Option:
A. 9 cm
B. 18 cm
C. 20 cm
D. 41 cm
Answer: B . 18 cm
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Justification:
Diagonal of the rectangle D = Sq. root of 41 => D^2 = 41 => L^2 + B^2 = 41
Area of the rectangle A = L * B = 20 Sq. cm
Perimeter of the rectangle P = 2* (L + B)
=> (L + B)^2 = L^2 + 2LB + B^2 = 41 + 2*20 = 81 => (L+B) = 9
=> P = 2 * 9 = 18 cm.
