To convert degrees to radians, you can use the formula:
\[ \text{radians} = \text{degrees} \times \left(\frac{\pi}{180}\right) \]
For 72 degrees:
\[ \text{radians} = 72 \times \left(\frac{\pi}{180}\right) = 72 \times \frac{\pi}{180} = \frac{72\pi}{180} \]
Now, simplify \(\frac{72}{180}\):
\[ \frac{72}{180} = \frac{2}{5} \]
Therefore:
\[ \text{radians} = \frac{2\pi}{5} \]
So, 72 degrees is equal to \(\frac{2\pi}{5}\) radians.