Circles
The radius goes from the center to the edge of the circle. The diameter passes through the center and is twice the radius.
Diameter = radius × 2
Radius = diameter ÷ 2
Example
Radius 6 cm. Diameter = 6 × 2 = 12 cm
The radius goes from the center to the edge of the circle. The diameter passes through the center and is twice the radius.
Diameter = radius × 2
Radius = diameter ÷ 2
Radius 6 cm. Diameter = 6 × 2 = 12 cm