The answer for radius is 4.2 cm. The answer for diameter is 8.4 cm.
Step-by-step explanation:
If the line cuts halfway through the middle it is a radius, as you can see there. It says 4.2 cm, so that's your radius. If the line is straight through the circle and not cut in half then it is a diameter. The radius is half of the diameter. So if you add 4.2 or multiply 4.2x2 then you get 8.4 which is your diameter.
