Question

Find in cm the diameter of a circle whose radius is 85 mm.

Answer 1

The radius is half the diameter, likewise the diameter it double the radius.

the diameter is 170 mm

then with handy danddy google we get 1.7 cm as the answer you are looking for

P.S. 1 cm = 100 mm

Answer 2

Well, you first have to convert the 85 mm to cm, which you divide it by 100, and you get 8.5 cm, then add that with itself and you get 17 cm.