A sector of a circle has a central angle of 80 degrees. If the area of the sector is 35pi, what is the radius of the circle?
+36916 The sector of 80 degrees is a fraction of the TOTAL 360 degrees of the circle : 80 / 360
The area of a circle is given by Area = pi r^2
so for this sector
Area = 80 / 360 pi r^2
35 pi = 80 / 360 pi r^2 divide both sides by pi
35 = 80 / 360 r^2
35 * 360/80 = r2 Can you finish from here ?? 
