An error 4% in excess is made while measuring the side of a square. The percentage of error in the calculated area of the square is  Choose one
A) 8.04 %	B) 8.14 %	C) 8.23 %	D) 8.16 %	E) 8.5 %

Rationale: "100 cm is read as 102 cm . a 1 = ( 100 x 100 ) cm 2 and a 2 ( 102 x 102 ) cm 2 . ( a 2 - a 1 ) = [ ( 104 ) 2 - ( 100 ) 2 ] = ( 104 + 100 ) x ( 104 - 100 ) = 816 cm 2 . percentage error = 8.16 d"
Answer: D