Projectile motion question plzzzz helppp meeee !!!?

a projectile is launched at a velocity of 125m/s at an angle of 20 degrees.a building is 200m away.at what height above the ground will the projectile strike the building.correct answer is 50.6m..how this answer came please solve in detail?plus i tried to solve it by formula maximum height=v^2sin^2x/2g but this maximum height formula didn't work y is that so?