I got this:
Tennis court is a rectangle
(Rectangle - 2 sides the same length and the other 2 sides the same. So 2 pairs of equal length sides)
If one is 27 the other has got to be 27 as well - 27+27= 54
210 - 54 = 156
156 / 2 = the other "pair"
Hope that helps and correct me if I'm wrong!
the circumference is 20pie or 62.83185307
It opens down.
Since the beginning number -5x^2 is negative, it will open down.