Match each circumference to the corresponding radius or diameter of the circle. (all circumferences are approximate.) tiles circumference: 34.54 units circumference: 59.66 units circumference: 23.236 units circumference: 26.376 units circumference: 13.188 units circumference: 29.83 units pairs radius: 4.2 units diameter: 7.4 units diameter: 11 units radius: 9.5 units

We solve for the diameters of radius of the given circles by using the equation,
                                      C = πD
                    or               C = 2πr
where D and r are diameter and radius, respectively.

Solving,
      C = 34.54 units
                                D = C/π = 34.54 units / 3.14 = 11 units
                                r = C / 2π = 34.54 units/2(3.14) = 5.5 units

      C = 59.66 units
                                D = C/π  = 59.66 units/3.14 = 19 units
                                 r = D2 = 9.5 units
      C = 23.236 units
                                D = 23.236 units/3.14 = 7.4 units
                                 r = D/2 = 3.7 units
       C = 23.376 units
                                 D = 23.376 units / 3.14 = 7.4 units
                                    r = D/2 = 3.7 units
        C = 13.188 units
                                  D = 13.188 units/3.14 = 4.2 units
                                    r = D/2 = 2.1 units