Answer:
7pi/theta = radius
Explanation:
So we are using the arc length, central angle(in radians), and radius.
We know arc length, which is 7pi.
We don't know theta, which does not matter.
And finally, we don;t know radius, which is what we are looking for.
To find radius, we use:
arc length/theta=radius
Lets plug in our values:
7pi/theta=radius.
So the answer to the khan acadamy question is
7pi/∅
Here are some othr things that may help:
Radian * Radius = arc length
This solves for arc length
Here is another one:
Arc length/radius= radian
This solves for radians
Hope these help! :)