Final answer:
The 13.2 represents the amplitude of the seismic wave, indicating the maximum displacement from the rest position.
Step-by-step explanation:
The 13.2 in the equation r = 13.2 sin(θ), where r is the radius in miles, represents the amplitude of the seismic wave.
The amplitude is the maximum displacement of a point on the wave from its rest position, which in the context of an earthquake, can be thought of as the maximum distance the earth's surface moves from its normal position as the wave passes.
In the given equation r = 13.2 sin(θ), the 13.2 represents the amplitude of the seismic wave.
The amplitude is the maximum displacement of the wave from its equilibrium position. In this case, it represents the maximum distance that the seismic wave travels from its mean position.