Please help! I'll mark brainliest!! :)

Answer:
Area = 201 1/4 yard^2
Or in decimal form: 201.25 yard^2
Step-by-step explanation:
First convert the mixed numbers into improper fractions or even decimal form so it is easier to operate with them:
Base = 11 1/2 yards = 23/2 yards = 11.5 yards
Height = 17 1/2 yards = 35/2 yards = 17.5 yards
Use the formula for the area of a parallelogram:
Area = Base x Height
which in our case give:
Area = 23/2 x 35/2 = 805/4 yard^2 = 201 1/4 yard^2
Or in decimal form: 201.25 yard^2