Answer
$67.1^\circ$
Work Step by Step
1. Draw a diagram as shown in the figure.
2. The angle that the wire makes with the ground is $\theta$, we have $sin\theta=\frac{71.3}{77.4}\approx0.9212$
3. Use a scientific calculator, $\theta=asin(0.9212)\approx67.1^\circ$ (here $asin=arcsin=sin^{-1}$)
