Circumference

Master circle circumference! Explore radius, diameter, and pi with fun calculations and real-world problems.

The circumference of a circle is: Distance from the outside to the center. Distance from one side through the middle to the other side. Distance around the circle. What is one of the formulas for circumference? C = 2(pi)r C = 2r C = (pi) r2 What number do we always use for pi? 3.14 31.4 0.314 314 Link the correct radius to their diameter. d = 15 r = 7.5 d = 8 r = 4 r = 20 d = 40 d = 3.5 r = 1.75 r = 0.5 d = 1 Label the parts of the circle. Click on each blue dot to label that part, double check spelling from the word bank! You options are: radiusdiametercircumference Diameter Radius Circumference A mouse wheel was 10 inches in diameter. How far would the mouse run with one full rotation? Round your answer to the nearest tenth and use 3.14 for pi. 31.4 in. 314.2 in. 15.7 in. 78.5 in. From the center of the Frisbee to the outside was 6.5 inches (THINK: Is this radius OR diameter). What is the circumference of the Frisbee? Round your answer to the nearest tenth. 20.4 inches 40.8 inches 10.2 inches The crust of an entire pizza was about 50.3 inches (circumference). What is the radius of the pizza? about 25 inches about 16 inches about 8 inches about 50 inches about 4 inches