Question

For an angle y°, find:
(i) its supplementary angle.
(ii) its complementary angle.
(iii) the value of y° if its supplement is four times its complement.

Answer 1

For an angle y 

(i) Its supplementary angle = 180° - y

(ii) Its complementary angle = 90° - y

(iii) ∴ supplementary angle of y = 4   ...(complementary angle of y)

∴ 180° - y = 4 (90° - y)

⇒ 180° - y = 360° - 4y

⇒ 4y - y = 360° - 180°

⇒ 3y = 180°

⇒ y = `180^circ/3 = 60^circ`

∴ y = 60°