Two identical small insulating balls are suspended by separate 0.27 m threads that are attached to a common point on the ceiling. Each ball has a mass of 6.20 10-4 kg. Initially the balls are uncharged and hang straight down. They are then given identical positive charges and, as a result, spread apart with an angle of 20° between the threads.

Question

Two identical small insulating balls are suspended by separate 0.27 m threads that are attached to a common point on the ceiling. Each ball has a mass of 6.20  10-4 kg. Initially the balls are uncharged and hang straight down. They are then given identical positive charges and, as a result, spread apart with an angle of 20° between the threads. 
(a) What is the charge on each ball?
q =  ----------C

(b) What is the tension in the threads?
F =  ---.0062---N

cant figure out part (a) show all workings pliz