Tough question!

First you have to convert the measurements to be the same.

1 MM = 1000th of a meter or .001M

The formula for finding the circumference of a circle is Pi times D (diameter)

Remember the diameter of a circle is twice the radius

Pi = 3.14

So, 3.14* D = 1.5M

3.14D = 1.5

D = 1.5/3.14

D = .477707M

The radius would be half of that, or .2388535M

Now you need to convert back to MM

Multiply .2388535M times 1000 = 238.8535MM

Proof:

Let's convert to MM to begin with and see if we get the same answer

C = 1.5 M = 1500MM

C = Pi * D

C = 1500 divided by 3.14 = 477.707MM in diameter

The radius would be 1/2 of the diameter = 477.707MM/2 = 238.8535

Hope this helps

First you have to convert the measurements to be the same.

1 MM = 1000th of a meter or .001M

The formula for finding the circumference of a circle is Pi times D (diameter)

Remember the diameter of a circle is twice the radius

Pi = 3.14

So, 3.14* D = 1.5M

3.14D = 1.5

D = 1.5/3.14

D = .477707M

The radius would be half of that, or .2388535M

Now you need to convert back to MM

Multiply .2388535M times 1000 = 238.8535MM

Proof:

Let's convert to MM to begin with and see if we get the same answer

C = 1.5 M = 1500MM

C = Pi * D

C = 1500 divided by 3.14 = 477.707MM in diameter

The radius would be 1/2 of the diameter = 477.707MM/2 = 238.8535

Hope this helps