Tilted Cup of Water
A cup of water in the shape of a conical frustrum is tilted as shown. The base diameter is 5 cm, and the top diameter is 9 cm. The slant height is 12 cm. If the water touches the rim of the cup on one end and is 7 cm from the base on the other, then by what angle \( \theta \) (in degrees) is the cup turned from the upright position?