Answer: 165,900 km
Step-by-step explanation:
diameter is a straight line between two points on the circumference of a circle that passes between the center of the circle.
so if a penny has a diameter of 7.9 x 10^-5 km, and when placed end to end will require 2.1 x 10^9 pennies to circle the equator once, that means;
the approximate length of the equator will be:
7.9 x 10^-5 km x 2.1 x 10^9 pennies
= 165,900 km
