Answer
Arc EF = 52°
Arc HD = 142°
Angle HGF = 128°
Explanation
To solve for the unknown angles, we need to first solve for x
To do that, we need to first note that the sum of angles on a straight line is 180°
So,
Angle HCG + Angle HCD = 180° (Sum of angles on a straight line)
Angle HCG = 2x
Angle HCD = 6x + 28°
Angle HCG + Angle HCD = 180°
2x + 6x + 28° = 180°
8x + 28° = 180°
8x = 180° - 28°
8x = 152°
Divide both sides by 8
(8x/8) = (152°/8)
x = 19°
Angle HCG = 2x = 2 (19°) = 38°
Angle HCD = 6x + 28° = 6(19°) + 28° = 142°
So, we can solve for the rest now
Arc EF = Angle ECF
= 90° - Angle ECD
Angle ECD = Angle HCG = 38° (Vertically opposite angles are equal)
Arc EF = Angle ECF
= 90° - Angle ECD
= 90° - 38°
= 52°
Arc HD = Angle HCD = 142°
Angle HGF = Angle HCG + Angle GCF = 38° + 90° = 128°
Hope this Helps!!!
