What must radius of the plates in the designed capacitor be

Question: A 5.00 - pF parallel-plate air-filled capacitor with circular plates is to be used in a circuit in which it will be subjected to potentials of up to 1.00ï ½102V. The electric field between the plates is to be no greater than 1.00�104N/C. As a budding electrical engineer for Live-Wire Electronics, your task is to design the capacitor by finding what its physical dimensions and separation must be.

What must the radius of the plates in the designed capacitor be?

What must the separation of the plates in the designed capacitor be?

Find the maximum charge these plates can hold.