Geometry

Question Analysis:
This question applies the exterior angle sum property to an irregular triangle.

Key Concept Explanation:
- The sum of exterior angles for any polygon (including triangles) is 360°
- This applies to both regular and irregular polygons

Step-by-Step Solution:
1. Sum of given exterior angles: 110° + 130° = 240°
2. Third exterior angle = 360° - 240° = 120°

Common Mistakes:
- Using the triangle's interior angle sum (180°) instead of exterior angle sum
- Arithmetic errors in adding the given angles
- Forgetting that t...