Area of a circumference=π*r²for diameter=21.2 cm---------> r=10.6 cmA=π*10.6²--------> A=π*112.36 -------> A=352.81 cm²if 2π radians (full circumference) has an area of -----------------> 352.81 cm² 3π/5 radians-------------------------------------> XX=[(3π/5)*(352.81)]/2π---------> X=105.84 cm²