Drag and drop an answer to each box to correctly complete the derivation of a formula for the area of a sector of a circle suppose a sector of a circle with radius has a central angle of 8 since a sector is a fraction of a full circle, the ratio of a sector's area a to the circle's area is equal to the ratio of the to the measure of a full rotation of the circle a full rotation of a circle is 2x radians. this proportion can be written as 4 = multiply both sides by #r? and simplity to get where is the measure of the central angle of the sector and r is the radius of the circle