Gloria is planning to ride her bicycle near the transmitter of a radio station. She will be

Question

riding from a point 10 miles due east of the transmitter on a straight road to a point 40 miles
west and 10 miles north of the transmitter. She has a radio on her bicycle which can pick
up the station as long as she is within 10 miles of it. If she rides at a constant speed of 16 miles per hour, for what length of time during her ride will she be able to listen to the radio station?