Acircular plate has circumference 21.4 inches. what is the area of this plate? use 3.14 for pi.

What is the exact volume of the cylinder (radius 13 in., height 30 in.)

Jacob signs up to work for 2 1/2 hours at the school carnival. if each work shift is 3/4 hour, how many shifts will jacob work? (i just want to double check : |, for anybody that responds! : )

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?