We are given that one of the sides of the rectangle has length 3. This implies that either x or x + 6
equals 3. If x + 6 equals 3, then x must be –3, which is impossible since a length cannot be negative. Hence,
x = 3 and x + 6 = 3 + 6 = 9. The area of the rectangle, being the product of two adjacent sides of the
rectangle, is x(x + 6) = 3(9) = 27. The answer is (D).