A pendulum made of a string and a sphere is able to swing in a vertical plane. The pendulum is released from?

a position of 66 degrees from vertical. The string hits a peg located a distance d below the point of suspension and rotates about the peg. The acceleration of gravity is 9.8 m/s2. Find the smallest value of d (highest peg position) in order for the sphere to swing in a full circle centered on the peg. Answer in units of m.