Radius = diameter/2 = 5 cm
10cm
20 cm
it is half the diameter e.g 10cm diameter = 5 cm radius
radius = diameter ÷ 2 ⇒ radius = 10 cm ÷ 2 = 5 cm
10cm or 0.05meters
That depends what you mean with "a 20 cm. circle". If 20 cm. is the radius, you already have the answer. If 20 cm. is the diameter, the radius is half the diameter. (10cm)
if a radius is 5cm the diameter is 10cm rule- you double the radius
Take "pi" times the diameter of the circle. Pi = 3.14159 (ALWAYS) If circle has a diameter of 10cm, circumference 31.41cm If circle has a radius of 2inches, the circumference is 12.57 inches. (radius = 2, diameter = 4)
The circumference of a circle with radius of 10cm is: 62.83 cm
diameter=10cm radius=5cm
A circle of radius 10cm has a circumference of 2πr cm = 2π x 10 = 62.83 cmIf the diameter equalled 10cm then the radius equalled 5 cm and the circumference of this circle = 2π x 5 = 31.42 cm