if the circumference is
So I'm asuming you have a circle with a circumference of
If the angle that forms the sector is given in radians, then we can use the formula:
In this case,
We don't know the radius, therefore we must find it first.
The circumference of a circle is given by:
Now we can calculate the area of the sector:
... Or maybe, you meant the are of the whole circle is
The solution is found in a similar way, only we will have to define two areas. The area for the whole circle and the area of the sector:
Aw is the area of the Whole circle.
Now calculate the area of the sector in the same way we did before:
This answer looks much better, which is why I think this is more correct.
Sorry for the inconvienience