I cant figure out this problem:

"A baseball leaves the hand of the first baseman at an angle of θ with the horizontal and initial velocity of v(subscript 0)=80 feet per second. The ball is caught by the second baseman 100 feet away. Find θ if the range, r, of a projectile is given by r=1/32vē sin2θ. (note: the range is the horizontal distance the ball travels.)