claim: Pythagoras was an Ionian Greek person who used an extensive knowledge of mathematics in his work.
evidence: Inner Crater is the topographic feature that embraces the crater within the floor of Main Crater , at the summit of Mount Erebus , Ross Island , Antarctica .. Main Crater. Main Crater. Mount Erebus. Mount Erebus. Ross Island. Ross Island. Inner Crater contains an active anorthoclase -- phonolite lava lake .. anorthoclase. anorthoclase. phonolite. phonolite. lava lake. lava lake. The name is derived from the fact that the crater is within the Main Crater of Mount Erebus .. Main Crater. Main Crater. Mount Erebus. Mount Erebus