Find the radian measures corresponding to the following degree measures: (i) 25° (ii) 137°30' (iii) 240° (iv) 520°

We know that ,180°=π radian
(i)25°=π/180 ×25=5π/36 radian
(ii)137°30' =137.5° [∵1°=60'] = 137.5 × π/180 radian =(137.5 × 2)π radian = 137.5π/180 radian =275π/360 radian = 55π/72 radian
(iii)240°=π/180 ×240=4π/3 radian
(iv)520°=π/180 ×520 radian=26π/9 radian