235 BC

Events in 235 BC 1

• 235 BC On the Sphere and Cylinder The volume and surface area of a sphere — his proudest achievement In his two-volume On the Sphere and Cylinder, Archimedes proved that the surface area of a sphere is 4πr², and that the volume of a sphere is exactly two-thirds the volume of the cylinder that just encloses it. He was so proud of this result that he requested it be engraved on his tomb — a sphere inside a cylinder. When the Roman statesman Cicero visited Syracuse in 75 BC, he found the neglected tomb of Archimedes and confirmed the engraving. The result was not rediscovered by European mathematics until the 17th century.