Question

Convert the following degree measure into radian measure.

i)  45°

ii) 25°

iii) 240°

iv) 40°20′

v) -47°30′

Answer 1

(i) 45° = 45 \(\times \frac{\pi}{180} = \frac{\pi}{4}\)

(ii) 25° = 25 \(\times \frac{\pi}{180} = \frac{5\pi}{36}\)

(iii) 240° = 240 \(\times \frac{\pi}{180} = \frac{4\pi}{3}\)

(iv) 40° 20' = 40 \(\frac{l}{3}\times \frac{\pi}{180}\) = \(\frac{121 \pi}{3 \times 180} = \frac{121 \pi}{540}\)

(v) -47° 30'= \(-47 \frac{1}{2} \times \frac{\pi}{180}\) = \(\frac{95\pi}{2 \times 180}= \frac{19\pi}{72}\)