Suppose you are visiting the equator. It is noon. The Sun is at its highest point in the sky for the day, which is directly over your head. You call a friend on the phone, and
she says it is also noon where she is but the Sun is not directly overhead at that
location and time. It is a little lower in the sky for her. Compare the longitude and
latitude where you are with the longitude and latitude where your friend is. Are they
alike or different? How do you know?