You have all the information you need to find the area of the circle and then subtracting that from 77 you'll have the area of the rectangle and will be able to figure out the length and height by looking at the answer options.
So the area of a triangle is 1/2(b x h) or (b x h)/2 so the base is 6 and the height is 9 so the area is 54/2 which equals 27. 77 - 27 = 50 so the area of the rectangle is 50. With the answer options provided I can see that <em>the height of the rectangle is 5 and the length is 10.</em>
