The (small) challenge here is to determine what the LCD is. Since 11, 17 and 3 are all prime, we find the LCD by multiplying them together: 561.
Then 9/11= 459/561; 15/17 = 495/561; and 2/3 = 375/561.
They are either the same, or opposite number.
Multiply the two as area is base times height.