what is the area of the square with the following coordinates : ( x , y ) , ( 20 , 20 ) , ( 20 , 9 ) , ( x , 9 ) ?
to find the area of a square , knowing the length of one side is sufficient . from the coordinates given , we can see that one side equals 11 . the area is 11 * 11 = 121 . the answer is a .
square_area(subtract(20, 9))