Resposta:
[tex]\frac{A_1}{A_2} =\frac{1}{4}[/tex]
Explicação passo-a-passo:
[tex]\frac{r}{R}=sen30^o \\\\\frac{r}{R}= \frac{1}{2}\\\\R=2r\\\\A_1=\pi r^2\\\\A_2=\pi R^2\\\\A_2=\pi (2r)^2\\\\A_2=4\pi r^2\\\\\frac{A_1}{A_2}=\frac{\pi r^2}{4\pi r^2}\\\\\frac{A_1}{A_2} =\frac{1}{4}[/tex]
