1. (a) Obtuse (b) Reflex (c) Acute (d) Obtuse (e) Acute
2. (a) a = 70° (adj. s on st. line are supp.)
(b) b = 61° (adj. s on st. line are supp.)
(c) c = 50° (s of add to 180°)
(d) d = 70° (adj. s on st. line are supp.)
e = 52° (s of add to 180°)
(e) f = 113° (s at a point add to 360°)
(f) g = 47° (vert. opp. s are equal)
h = 82° (s of add to 180°)
(g) j = 115° (s of a quad. add to 360°)
k = 65° (adj. s on st. line are supp.)
(h) l = 97° (vert. opp. s are equal)
m = 83° (adj. s on st. line are supp.)
n = 83° (vert. opp. s are equal)
(i) p = 131° (adj. s on st. line are supp.)
q = 68° (s of add to 180°)
r = 63° (adj. s on st. line are supp.)
(j) t = 80° (s of a add to 180°)
u = 16° (s of a add to 180°)
3. (a) x = 60° y = 60°
(b) a = 75°, b = 105°
(c) c = 48°, d = 48°, e = 92°
(d) f = 38°, g = 64°, h = 78°
(e) k = 45°, j = 75°
(f) m = 82°, n = 119°, p = 61°, q = 37°