Answer:
A= 48°
B= 60°
C= 72°
D= 20°
E= 20°
F= 160°
G= 160°
Step-by-step explanation:
A= 180° -90° -42° (∠ sum of △)
A= 48°
D= 180° -42° -28° -90° (∠ sum of △)
D= 20°
E= D (vert. opp. ∠s)
E= 20°
G= 180° -D (adj. ∠s on a str. line)
G= 180° -20°
G= 160°
F= G (vert. opp. ∠s)
F= 160°
C= 180° -88° -D (∠ sum of △)
C= 180° -88° -20°
C= 72°
A +B +C= 180° (adj. ∠s on a str. line)
48° +B +72°= 180°
B +120°= 180°
B= 180° -120°
B= 60°
☆The sum of angles on a straight line is 180°
☆ The sum of angles in a triangle is 180°
