Answer: 7.2 cm
Explanation: It's important to understand that the radius is equal to half of the diameter so to find the diameter of a circle with a radius of 3.6 cm, we simply multiply 3.6 cm by 2 and we will get the diameter or the distance across a circle.
To multiply a decimal times a whole number such as 3.6 x 2, first line up the numbers and begin multiplying as if we were multiplying 2 whole numbers.
6 x 2 is 12 so we bring down the 2 and carry the 1.
2 x 3 is 6 and if we add 1 we get 7.
So we have 7.2 cm which is our diameter