A diver looking up through water (μ=4/3) sees the outside world contained in a circular area on the surface of water. If the diver's eyes are √ 7 m…

$\displaystyle \operatorname{Sin} \mathrm{C}=\frac{1}{\mu}$ Sin $\displaystyle \mathrm{C}=\frac{3}{4}$ $\displaystyle \operatorname{Sin} \mathrm{C}=\frac{R}{\sqrt{R^{2}+7}}$ $$\begin{aligned} \frac{3}{4} & =\frac{R}{\sqrt{R^{2}+7}} \\ R & =3 \mathrm{~m} \\ \text { Area } & =\pi R^{2} \\ & =3.14 \times(3)^{2} \\ & =28.26 \mathrm{~m}^{2} \end{aligned} $$