Find the area of the square, one of whose diagonals is 3.8 m long ?  Pick one
A) 7.22 m ^ 2
B) 3.86 m ^ 2
C) 8.96 m ^ 2
D) 2.68 m ^ 2
E) 7.89 m ^ 2

Rationale: area of the square = 1 / 2 ( diagonal ) ^ 2 = ( 1 / 2 * 3.8 * 3.8 ) m ^ 2 = 7.22 m ^ 2 answer ( a )
Answer: A