## Elementary Geometry for College Students (5th Edition)

The angle of depression from the ballon is $\approx 8^{\circ}$.
Refer to the attachment: $B =$ Hot air Balloon $D =$ Stadium $α =$ Angle of depression from the hot air balloon $AB = 300$ ft $BD = 2200$ ft 1. Find $\angle x$ in the triangle $\triangle ABD$ using the sine law $\frac{sin(x)}{AB} = \frac{sin90}{BD}$ $\frac{sin(x)}{300} = \frac{sin90}{2200}$ $sin(x) = \frac{300sin90}{2200}$ $sin(x) = \frac{300}{2200}$ $sin(x) = \frac{300}{2200}$ $sin(x) = 0.1364...$ $x = sin^{-1}(0.1364...)$ $x = 7.84^{\circ}$ $x \approx 8^{\circ}$ 2. Apply the concept of alternate angles $x = α$ (Because of alternate angles) Therefore, $α \approx 8^{\circ}$.