Final answer:
The circumference of the Earth, or the equator, is calculated using the formula C = 2πr, where r is the radius. Given Earth's approximate radius of 6400 km, the circumference is approximately 40,212 km. This showcases the application of geometric formulas to determine real-world measurements.
Step-by-step explanation:
The circumference of the Earth, which is also referred to as the equator, can be calculated by using the formula for the circumference of a circle, which is C = 2πr where π (pi) is approximately 3.14159 and r is the radius of the circle. Given that the radius of the Earth is approximately 6400 km, the circumference would be C = 2π(6400 km) ≈ 2(3.14159)(6400 km) ≈ 40,212 km.
To provide further clarity, Earth's diameter is about 12,700 km, and using this value, one can still determine the circumference by applying the relation that the diameter is twice the radius (D = 2r), followed by using the circumference formula resulting in the same approximate circumference. This is a practical application of basic geometry and the way it can be employed to understand large-scale real-world measurements such as the size of our planet.