Add, subtract multiply

The circumference of a circle is 5 pi cm. what is the area of the circle?

Alake near the arctic circle is covered by a 222-meter-thick sheet of ice during the cold winter months. when spring arrives, the warm air gradually melts the ice, causing its thickness to decrease at a constant rate. after 333 weeks, the sheet is only 1.251.251, point, 25 meters thick. let s(t)s(t)s, left parenthesis, t, right parenthesis denote the ice sheet's thickness sss (measured in meters) as a function of time ttt (measured in weeks).

Points a, b, and c form a triangle. complete the statements to prove that the sum of the interior angles of triangle abc is 180