Converting between degrees and radians is an important skill for working with angles in trigonometry and the unit circle. To convert degrees to radians, multiply by \(\frac{\pi}{180^\circ}\), and to convert radians to degrees, multiply by \(\frac{180^\circ}{\pi}\). These problems practice both directions, including positive angles, negative angles, improper radian measures, and common unit-circle angles.
Notes

Practice Problems
\(\textbf{1)}\) Convert \( \theta=55^{\circ} \) from degrees to radians
The answer is \( \displaystyle\frac{11\pi}{36} \) radians
\(\text{Degrees } \rightarrow \text{ Radians}\)
\(\,\,\,\,\, 55^{\circ} \times \displaystyle \frac{\pi}{180^{\circ}}=\frac{55\pi}{180}=\frac{11\pi}{36}\)
\(\textbf{2)}\) Convert \( \theta=270^{\circ} \) from degrees to radians
The answer is \( \displaystyle\frac{3\pi}{2} \) radians
\(\text{Degrees } \rightarrow \text{ Radians}\)
\(\,\,\,\,\, 270^{\circ} \times \displaystyle \frac{\pi}{180^{\circ}}=\frac{270\pi}{180}=\frac{3\pi}{2}\)
\(\textbf{3)}\) Convert \( \theta=-275^{\circ} \) from degrees to radians
The answer is \( – \displaystyle\frac{55\pi}{36} \) radians
\(\text{Degrees } \rightarrow \text{ Radians}\)
\(\,\,\,\,\, -275^{\circ} \times \displaystyle \frac{\pi}{180^{\circ}}=\frac{-275\pi}{180}=\, – \frac{55\pi}{36}\)
\(\textbf{4)}\) Convert \( \theta=140^{\circ} \) from degrees to radians
The answer is \( \displaystyle\frac{7\pi}{9} \) radians
\(\text{Degrees } \rightarrow \text{ Radians}\)
\(\,\,\,\,\, 140^{\circ} \times \displaystyle \frac{\pi}{180^{\circ}}=\frac{140\pi}{180}=\frac{7\pi}{9}\)
\(\textbf{5)}\) Convert \( \theta=-36^{\circ} \) from degrees to radians
The answer is \( – \displaystyle \frac{\pi}{5} \) radians
\(\text{Degrees } \rightarrow \text{ Radians}\)
\(\,\,\,\,\, -36^{\circ} \times \displaystyle \frac{\pi}{180^{\circ}}=\frac{-36\pi}{180}=\, – \frac{\pi}{5}\)
\(\textbf{6)}\) Convert \( \theta=400^{\circ} \) from degrees to radians
The answer is \( \displaystyle\frac{20\pi}{9} \) radians
\(\text{Degrees } \rightarrow \text{ Radians}\)
\(\,\,\,\,\, 400^{\circ} \times \displaystyle \frac{\pi}{180^{\circ}}=\frac{400\pi}{180}=\frac{20\pi}{9}\)
\(\textbf{7)}\) Convert \( x=\displaystyle\frac{-7\pi}{5} \) from radians to degrees
The answer is \( -252^{\circ} \)
\(\text{Radians } \rightarrow \text{ Degrees}\)
\(\,\,\,\,\, \displaystyle\frac{-7\pi}{5} \times \displaystyle \frac{180^{\circ}}{\pi}=-252^{\circ}\)
\(\textbf{8)}\) Convert \( x=\displaystyle\frac{-5\pi}{3} \) from radians to degrees
The answer is \( -300^{\circ} \)
\(\text{Radians } \rightarrow \text{ Degrees}\)
\(\,\,\,\,\, \displaystyle\frac{-5\pi}{3} \times \displaystyle \frac{180^{\circ}}{\pi}=-300^{\circ}\)
\(\textbf{9)}\) Convert \( x=\displaystyle\frac{4\pi}{5} \) from radians to degrees
The answer is \( 144^{\circ} \)
\(\text{Radians } \rightarrow \text{ Degrees}\)
\(\,\,\,\,\, \displaystyle\frac{4\pi}{5} \times \displaystyle \frac{180^{\circ}}{\pi}=144^{\circ}\)
\(\textbf{10)}\) Convert \( x=\displaystyle\frac{\pi}{8} \) from radians to degrees
The answer is \( 22.5^{\circ} \)
\(\text{Radians } \rightarrow \text{ Degrees}\)
\(\,\,\,\,\, \displaystyle\frac{\pi}{8} \times \displaystyle \frac{180^{\circ}}{\pi}=22.5^{\circ}\)
\(\textbf{11)}\) Convert \( x=\displaystyle\frac{5\pi}{12} \) from radians to degrees
The answer is \( 75^{\circ} \)
\(\text{Radians } \rightarrow \text{ Degrees}\)
\(\,\,\,\,\, \displaystyle\frac{5\pi}{12} \times \displaystyle \frac{180^{\circ}}{\pi}=75^{\circ}\)
\(\textbf{12)}\) Convert \( \theta=315^{\circ} \) from degrees to radians
The answer is \(\displaystyle\frac{7\pi}{4}\) radians
\(\text{Degrees } \rightarrow \text{ Radians}\)
\(\,\,\,\,\,315^{\circ}\times\displaystyle\frac{\pi}{180^{\circ}}=\frac{315\pi}{180}\)
\(\,\,\,\,\,\frac{315\pi}{180}=\frac{7\pi}{4}\)
\(\textbf{13)}\) Convert \( \theta=225^{\circ} \) from degrees to radians
The answer is \(\displaystyle\frac{5\pi}{4}\) radians
\(\text{Degrees } \rightarrow \text{ Radians}\)
\(\,\,\,\,\,225^{\circ}\times\displaystyle\frac{\pi}{180^{\circ}}=\frac{225\pi}{180}\)
\(\,\,\,\,\,\frac{225\pi}{180}=\frac{5\pi}{4}\)
\(\textbf{14)}\) Convert \( \theta=-150^{\circ} \) from degrees to radians
The answer is \(-\displaystyle\frac{5\pi}{6}\) radians
\(\text{Degrees } \rightarrow \text{ Radians}\)
\(\,\,\,\,\,-150^{\circ}\times\displaystyle\frac{\pi}{180^{\circ}}=\frac{-150\pi}{180}\)
\(\,\,\,\,\,\frac{-150\pi}{180}=-\frac{5\pi}{6}\)
\(\textbf{15)}\) Convert \( x=\displaystyle\frac{11\pi}{6} \) from radians to degrees
The answer is \(330^{\circ}\)
\(\text{Radians } \rightarrow \text{ Degrees}\)
\(\,\,\,\,\,\displaystyle\frac{11\pi}{6}\times\displaystyle\frac{180^{\circ}}{\pi}\)
\(\,\,\,\,\,\displaystyle\frac{11\cdot180^{\circ}}{6}=330^{\circ}\)
Challenge Problems
\(\textbf{16)}\) Convert \( x=-\displaystyle\frac{13\pi}{4} \) from radians to degrees
The answer is \(-585^{\circ}\)
\(\text{Radians } \rightarrow \text{ Degrees}\)
\(\,\,\,\,\,-\displaystyle\frac{13\pi}{4}\times\displaystyle\frac{180^{\circ}}{\pi}\)
\(\,\,\,\,\,-\displaystyle\frac{13\cdot180^{\circ}}{4}=-13\cdot45^{\circ}\)
\(\,\,\,\,\,-13\cdot45^{\circ}=-585^{\circ}\)
\(\textbf{17)}\) Convert \( \theta=765^{\circ} \) from degrees to radians
The answer is \(\displaystyle\frac{17\pi}{4}\) radians
\(\text{Degrees } \rightarrow \text{ Radians}\)
\(\,\,\,\,\,765^{\circ}\times\displaystyle\frac{\pi}{180^{\circ}}=\frac{765\pi}{180}\)
\(\,\,\,\,\,\frac{765\pi}{180}=\frac{17\pi}{4}\)
\(\textbf{18)}\) Convert \( x=\displaystyle\frac{19\pi}{10} \) from radians to degrees
The answer is \(342^{\circ}\)
\(\text{Radians } \rightarrow \text{ Degrees}\)
\(\,\,\,\,\,\displaystyle\frac{19\pi}{10}\times\displaystyle\frac{180^{\circ}}{\pi}\)
\(\,\,\,\,\,\displaystyle\frac{19\cdot180^{\circ}}{10}=19\cdot18^{\circ}\)
\(\,\,\,\,\,19\cdot18^{\circ}=342^{\circ}\)
\(\textbf{19)}\) Convert \( \theta=-720^{\circ} \) from degrees to radians
The answer is \(-4\pi\) radians
\(\text{Degrees } \rightarrow \text{ Radians}\)
\(\,\,\,\,\,-720^{\circ}\times\displaystyle\frac{\pi}{180^{\circ}}=\frac{-720\pi}{180}\)
\(\,\,\,\,\,\frac{-720\pi}{180}=-4\pi\)
\(\textbf{20)}\) Convert \( x=-\displaystyle\frac{17\pi}{12} \) from radians to degrees
The answer is \(-255^{\circ}\)
\(\text{Radians } \rightarrow \text{ Degrees}\)
\(\,\,\,\,\,-\displaystyle\frac{17\pi}{12}\times\displaystyle\frac{180^{\circ}}{\pi}\)
\(\,\,\,\,\,-\displaystyle\frac{17\cdot180^{\circ}}{12}=-17\cdot15^{\circ}\)
\(\,\,\,\,\,-17\cdot15^{\circ}=-255^{\circ}\)
See Related Pages\(\)