Geometry

Question Analysis:
This problem combines algebra with parallelogram angle properties, focusing on adjacent angle relationships.

Key Concept Explanation:
Essential parallelogram angle properties:
Adjacent angles are supplementary (sum to 180°)
Opposite angles are congruent
These properties hold universally for all parallelograms

Step-by-Step Solution:
Set up adjacent angles equation:
(4x + 10) + (6x - 20) = 180
Simplify and solve:
10x - 10 = 180 → 10x = 190 → x = 19
Calculate ∠E: 4(19) + 10 = 86°
Find ∠F: 6(19) - 20 = 94° (Verification: 86° + 94° = 180°)
Determine ∠G (opposite ∠E): ∠G = ∠E = 86°

Common Mistakes:
Miside...