Need help with a pendulum question!?

A 50kg pendulum bob hanging from a 45m cable swings freely after being relesased from some angle θ relative to vertical. If the cable suddenly broke at the very bottom of the pendulum's swing, the bob would continue in its path and eventually fall to the ground. If the horizontal distance the bob travels before it hits the ground is 20m, what was the angle θ that it was released from? The anchor point for the pendulum cable is 50m above the ground