Geometry

Question Analysis：
This word problem requires translating a verbal relationship into an algebraic equation.

Key Concept Explanation：
Parallelogram angle properties：
• Adjacent angles supplementary
• Opposite angles equal

Step-by-Step Solution：
Let ∠F = x
Then ∠E = x - 40
Set up equation：
(x - 40) + x = 180 → 2x = 220 → x = 110
Find angles：
∠F = 110°
∠E = 70°
∠G is opposite ∠E → ∠G = ∠E = 70°

Common Mistakes：
• Confusing which angles are oppo...