Chapter 2 - Acute Angles and Right Triangles - Section 2.4 Solving Right Triangles - 2.4 Exercises - Page 80: 53

The length of the shadow is 13.4 feet

Let $h$ be the person's height. We can use $h$ and $\theta$ to find the length $L$ of the shadow: $\frac{h}{L} = tan(\theta)$ $L = \frac{h}{tan~\theta}$ $L = \frac{5.75~ft}{tan~(23.4^{\circ})}$ $L = 13.4~ft$ The length of the shadow is 13.4 feet