Question

Difficulty: EasyUnit Circle and Angle Measures (Radians and Degrees)

Match each angle measure in degrees on the left to its equivalent angle measure in radians on the right.

  • 3030^\circπ6\frac{\pi}{6} radians
  • 4545^\circπ4\frac{\pi}{4} radians
  • 6060^\circπ3\frac{\pi}{3} radians
  • 9090^\circπ2\frac{\pi}{2} radians

Answer

The degree measures 3030^\circ, 4545^\circ, 6060^\circ, and 9090^\circ correspond to π6\frac{\pi}{6}, π4\frac{\pi}{4}, π3\frac{\pi}{3}, and π2\frac{\pi}{2} radians, respectively.
Each degree measure matches its correct radian value by multiplying the degree measure by π180\frac{\pi}{180^\circ} and simplifying the fraction.

Step-by-Step Solution

1
Apply the degree-to-radian conversion formula.
Multiply each degree measure by the conversion factor π180\frac{\pi}{180^\circ}.
A full circle has 360360^\circ or 2π2\pi radians, meaning 180=π180^\circ = \pi radians. Therefore, the conversion factor from degrees to radians is π180\frac{\pi}{180^\circ}.
2
Simplify the resulting fractions.
30×π180=π630^\circ \times \frac{\pi}{180^\circ} = \frac{\pi}{6}, 45×π180=π445^\circ \times \frac{\pi}{180^\circ} = \frac{\pi}{4}, 60×π180=π360^\circ \times \frac{\pi}{180^\circ} = \frac{\pi}{3}, and 90×π180=π290^\circ \times \frac{\pi}{180^\circ} = \frac{\pi}{2}.
Reducing the fractions by dividing the numerator and denominator by their greatest common factor gives the simplified radian values.

Key Concept

Converting degree measures to radian measures on the unit circle
Estimated Time:45s
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