Which of the following describes the contribution of Eratosthenes? A. discovery of the geocentric theory B. discovery of a mathematical formula to relate the sides of a right triangle C. calculation of the circumference of the world to within one percent D. calculation of the weight of ships by the amount of water they displaced

The correct answer is option C, calculation of the circumference of the world to within one percent.

Eratosthenes was a mathematician and astronomer from ancient Greece. He calculated the circumference of the Earth with reasonable accuracy by noting the position of the Sun's rays in two different locations.

Eratosthenes believed the Earth was a sphere and used trigonometry and geometry to calculate the distance around Earth.