Answer
$8.25\ m$
Work Step by Step
Using the definition of sine of the angle A, we have
$$
\sin A=\sin 29.7=\frac{length \ of \ side\ opposite\ angle\ A}{length \ of \ the\ hypotenuse }=\frac{4.09}{c}
.$$
That is,
$$
c= \frac{4.09}{\sin 29.7}=8.25\ m
.$$
