We can use Pythagorean's theorem to solve this problem:
a^2 + b^2 = c^2
a and b would both be the same value, since the shape is a square.
The sides of the square would each equal 30.
30^2 = 900
a^2 = 900 which means b^2 = 900
900 + 900 = 1,800
√1,800 ≈ 42.43
A diagonal of the playground would be about 42.43 yards!
