Solve equation with the quadratic 6b^2=-10+18

Aschool puts on a play. the play costs $1,200 in expenses. the students charge $4.00 for tickets. there will be one performance of the play in an auditorium that seats 500 people. what is the domain of the function that shows the profit as a function of the number of tickets sold?  

Ineed to know the answer right now! !

Ab based on the given diagram, if m_1 = 60° then m 2 = 30 60 90 180