Find the circumference of the circle:
Circumference = 2 x r x pi
Circumference = 2 x 200 x 3.14
Circumference = 1,256 feet.
4 inches/ 12 inches per foot = 0.333 ft.
Divide the circumference by the spacing:
1255/0.333 = 3,768
You will need 3,768 flowers