Anyone know how to solve these

You make and sell triangular flags. each flag has a base of  3.53.5  feet and a height of  2.52.5  feet. fabric for the flags costs  $0.40$0.40  per square foot. what is the cost to make one flag?

Find the x-intercepts of the parabola withvertex (1,1) and y-intercept (0,-3).write your answer in this form: (x1,if necessary, round to the nearest hundredth.

Can someone me out here and the tell me the greatest common factor