Calculus
posted by Calculus .
A runner sprints around a circular track of radius 150 m at a constant speed of 7 m/s. The runner's friend is standing at a distance 300 m from the center of the track. How fast is the distance between the friends changing when the distance between them is 300 m? (Round to 2 decimal places.

Still not getting this! My teacher has me so confused.
right now i have 2L(dL/dt)=2(150)(300)sin(theta)(dtheta/dt)
I think that the angle changes at 7/150 but idk =[ 
See repost:
http://www.jiskha.com/display.cgi?id=1285961612 
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