There are two semicircular carpets on the stage of the Spring Festival Evening. Their circumference is 25.7 meters. What is the total area of these two carpets?
The circumference of a semicircle = the length+diameter of semicircle = pi× r+2r = 25.7m, and the radius r = 25.7/(3.14159+2) = 5m. Two semi-circular carpets are spliced into a whole circle with a total area of pi× r× r = 3.65438+.