Test 7 Section 3 #18 please

To convert between radians and degrees, you just need to remember that a full circle, 360°, is the same as 2π radians. You can use that fact to solve any degree/radian conversion question with a simple ratio:

    \begin{align*}\dfrac{\text{angle in degrees}}{360^\circ}&=\dfrac{\text{angle in radians}}{2\pi}\end{align*}

In this case, we take the 720° we’re given and solve thusly:

    \begin{align*}\dfrac{720^\circ}{360^\circ}&=\dfrac{\text{angle in radians}}{2\pi}\\\\2&=\dfrac{\text{angle in radians}}{2\pi}\\\\4\pi&=\text{angle in radians}\end{align*}

That tells you that the a in  is equal to 4.