If each side of a rectangle is decreased by 11%, then its area will decrease by:

20.79%

11% = \(\frac{11}{100}\)

ATQ ,

Side 1  =    100     :     89

Side 2  =    100     :     89

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Area        10000    :     7921

{ Area of triangle = \(\frac{1}{2}\) × Side1 × Side 2 × sinθ }

Decreased percentage = \(\frac{2079}{10000}\) ×  100 =  20.79%