Respuesta :

EXPLAINATION:  [tex]\pi r^2=\frac{22}{7} .21^2=\frac{22}{7} .441=\frac{22.441}{7} =\frac{22.63.7}{7} =22.63=1386<cm^2>[/tex]  

ANSWER: 1386 [tex]cm^2[/tex]

Ok done. Thank to me :>