The formula for the area of a circle is:
A=πr²
Since the rope is connected to the center of this circle, and reaches the end of where the cow can possibly graze, the distance of the rope is the circles radius.
r=15ft
Now we can solve for the area of the circle
A=πr²
A=π15²
A=225π ft²
or if you needed to simplify further...
A=706.86ft²
Answer=706.86ft² or 225π ft² (both are equivalent)
