Since PQRS is a parallelogram, we know that QR = PS, so side PS also as length 10


Next, the area of a parallelogram = (base)(height)
The base has length 10 and we're told the area = 40
So, we get: (10)(height) = 40, which means the height = 4


We're also told that ST = 7


Since PS has length 10, we can conclude that PT has length 3


Now focus on the RIGHT TRIANGLE ∆PQT


When we apply the Pythagorean Theorem, we see that side PQ (the hypotenuse of ∆PQT) has length 5, which means the side opposite PQ (side RS) also has length 5


So, the perimeter of the parallelogram 10 + 5 + 10 + 5 = 30

Answer: A