<span>Let opposite ray be drawn for the base side ray of the given angle.
This gives angle 180° between these two rays.
Angle bisectors of the given angles 50°, 90°, and 150° make respectively half of these angles : 25° , 45° and 75° with the base ray.
Then measure of the angles between the bisectors of the given angles and the drawn opposite ray are 180°-25°=155°, 180°- 45° =135° and 180°- 75° = 105° respectively.</span>