Geometry

Question Analysis

This question involves finding the missing angle. The main focus is on understanding the properties of vertical angles.

Key Concept Explanation:

Vertical angles: Opposite angles formed by two intersecting lines. The key property is that vertical angles (formed by intersecting lines) are always congruent, regardless of whether the intersecting lines are parallel or not.

Step-by-Step Solution:

Check the position of angles 6 and 8 in the given diagram:

Notice that they are non-adjacent angles. And they are formed by the intersection of two lines and are opposite each other.

So ∠6 and ∠8 are vertical angles, so m∠8 = m∠6 = 120° (by Vertical Angles Theorem)

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