Finding the Measurement of a Half Angle

Now, we will return to the problem posed at the beginning of the section. A bicycle ramp is constructed for high-level competition with an angle of $\theta$ formed by the ramp and the ground. Another ramp is to be constructed half as steep for novice competition. If $tan\theta =\frac{5}{3}$ for higher-level competition, what is the measurement of the angle for novice competition?

Its source prints no answer for this problem, so there's nothing to check against.

OpenStax, Algebra and Trigonometry 2e · §9.3 Double-Angle, Half-Angle, and Reduction Formulas · Example 9