How many degrees should the pilot tilt the radar to measure the height of the storm?

A storm is 40 miles ahead of a plane in flight on left. Altitude is 37000 ft. How many degrees should the pilot tilt the radar to measure the height of the storm? (On a flight from SFO to IND the pilot announced that he would like a penger to tell him the answer and which equation to use to answer it. I hope he already knew the answer.)