Kiah wants to buy a flying disc for his friend. The radius of the disc is 15 cm. What is the length of the diameter

The diameter of a circle is equal to twice the radius. So in this case, the diameter would be:

Diameter = 2 * Radius
Diameter = 2 * 15 cm
Diameter = 30 cm

Therefore, the length of the diameter of the flying disc is 30 cm.