Ask a few questions about the mathematical circle. Find the circumference of a circle R = 8cm D = 9m. Find the area of the circle r=2.5 decimeters D = 0.6m meters.
Circumference: 8× 2× 3.14 = 50.24cm.
9× 314 = 28.26m.
Area: 2.5× 2.5× 3.14 =19.625 square decimeter.
0.6÷2=0.3 m 0.3×0.3×3. 14=0.2826 m2