ᴜᴛɪᴏɴ :-ANGLE between incident ray & mirror = 40°Reflection ray = ?Taking the NORMAL in the middle of the mirror . Now ,the ONE of the angle is 40° and the other angle will be 90° - 40° = 50° . So angle of incidence = 50° . As we know that , angle of incidence = angle of reflection . Hence, reflected angle = 50° . _____________________ ☞ ❷ Sᴏʟᴜᴛɪᴏɴ :-Angle between incident ray and reflected ray = 100°angle of reflection = ?From the above solution , angle of incidence = angle of reflection .So, 2( angle of incidence or reflection ) = 100° ⇒ 2 ( ∠i ) = 100° ⇒ ∠i = 100°/2 ⇒ ∠i = 50° ♦ ∠i = ∠r ⇒ ∠r = 50° _____________________ ☞ ❸ Sᴏʟᴜᴛɪᴏɴ :-Angle of incidence = 20°Angle of reflection = ? ♦ ∠i = ∠r ⇒ ∠r = 20° _____________________ ☞ ❹ Sᴏʟᴜᴛɪᴏɴ :-Angle of incidence = 20°Angle of GLANCE = ?Glancing angle :- Angle between incident ray and mirror is glancing angle ♦ ∠g = 90° - i ⇒ ∠g = 90° - 20° ⇒ ∠g = 70° _____________________ ☞ ❺ Sᴏʟᴜᴛɪᴏɴ :-Angle between incident ray and mirror [ angle of glancing ] = 30°Angle between reflected ray and mirror [ angle of glancing ] = ? ♦ Angle between incident ray and mirror = Angle between reflected ray and mirror ⇒ Angle of glancing = 30°