Find the diameter of the circle if its radius is 12 cm 3 cm 5 mm 10 in.

To solve this problem, remember that the diameter is a straight line connecting two points of the circle and passing through the center. In order to find the diameter along the radius, you need to double the radius.
1) r = 12 cm.
d = 12 * 2 = 24 cm.
2) r = 3 cm.
d = 3 * 2 = 6 cm.
3) r = 5 mm.
d = 5 * 2 = 10 mm.
4) r = 10 dm.
d = 10 * 2 = 20 dm.
Answer: 24 cm, 6 cm, 10 mm, 20 dm.