Earth has been charted with vertical and horizontal lines so that points can be named with coordinates. The T
horizontal lines are called latitude lines. The equator is
latitude line 0. Parallel lines are numbered up to - to the north
2
and to the south. If we assume Earth is spherical, the length of any parallel of latitude is equal to the circumference
a great circle of Earth times the cosine of the latitude angle.
a. The radius of earth is about 6400 kilometers. Find the circumference of a great circle.
b. Write an equation for the circumference of any latitude circle with angle e.
C. Which latitude circle has a circumference of about 3593 kilometers?
What is the circumference of the equator?