Answer:
Area: x^2 + 6x
Explanation:
1. This figure resembles a parallelogram, with it's dimensions parallel to the point of congruency. Even if it wasn't a parallelogram however, you would get the basic idea of calculating it's area by height * length.
2. Knowing the dimensions to be ( x + 6 ) by x, you can multiply them through algebra as such: x ( x + 6 ) ⇒ x^2 + 6x
3. Answer: x^2 + 6x