Respuesta :

[tex]\dfrac{18^o}{360^o}=\dfrac{1}{20}\\r=4\\\\A=\dfrac{1}{20}\cdot\pi\cdot4^2=\dfrac{1}{20}\pi\cdot16=\dfrac{16}{20}\pi=\dfrac{4}{5}\pi=0.8\pi\approx0.8\cdot3.14=2.512\\\\Answer:\boxed{A=2.512}[/tex]