Find the length of the circle if its radius is 3.5 cm.

The circumference is equal to the product of the diameter of a given circle by the number pi, constant in magnitude and equal to 3.14. To answer the question of the problem, you need to know the diameter of the circle. From the condition of the problem, the value of the radius of a given circle is known, which is half the diameter.
1) Calculate what is the value of the diameter of the circle.
3.5 * 2 = 7 centimeters.
Let’s answer the question of the problem.
2) Find what is the circumference.
7 * 3.14 = 21.98 centimeters.
Answer: The circumference is 21.98 centimeters.