Projectile Motion Problem?

If a cannon is fired at an angle 50 degrees from the horizontal, and its peak height is 21.7 meters, is it possible to find the initial velocity, the time the shot reaches its peak height, and the distance the cannon travels? I've tried substituting into the equations (∆y = 1/2*-g*t^2 + v*t) and (∆x = vt), but I'm always missing a variable. Please help?