2014-06-09 09:00:52

A square has a diagonal of 10 inches. What is its area?

(A) 25√2 square inches
(C) 25√3 square inches
(C) 50 square inches
(D) 50√2 square inches
(E) 100 square inches

 

The correct answer is A


Explanation: The diagonal of a square is equivalent to the length of one side of the square multiplied by √2. So if the diagonal is 10 inches, the square has sides of 10/√2. The area of a square is that squared, or (10/√2)(10/√2), which is 100/2, or 50.