The circumference of a circle is the distance of the outside of the circle. The formula for circumference is C=2πr.
In the question, you are given the diameter. Diameter is the radius times 2. So, to find the radius you can divide the diameter by 2. Since, 10cm/2 is 5 cm, 5cm is the radius.
Then, plug this information into the formula to solve for C.
2*5π = 10π
This means that, in terms of pi, the circumference is 10π cm.
