The relationship between degrees and radians is: $180^{\circ }=\pi \text{ radians}$ To convert $720^{\circ }$ to radians: $\theta =720^{\circ }\times \frac{\pi \text{ rad}}{180^{\circ }}=4\pi \text{ rad}$. Alternatively, since one full revolution is $360^{\circ }$ or $2\pi$ radians, $720^{\circ }$ is exactly two revolutions ($2\times 2\pi =4\pi$).