Change 160° and -22° 30' into radians, as fractions of π and as decimals to four places…

Step 1. $160^\circ$. $160 \times \dfrac{\pi}{180} = \dfrac{8\pi}{9} \approx 2.7925$ rad.

Step 2. $-22^\circ 30'$. This is $-22.5^\circ$, and $-22.5 \times \dfrac{\pi}{180} = -\dfrac{\pi}{8} \approx -0.3927$ rad.

Step 3. $\dfrac{11\pi}{18}$ rad. $\dfrac{11 \times 180^\circ}{18} = 110^\circ$.