Answers:
- a) 3 sides
- b) 3 vertices
- c) 3 interior angles
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Explanation:
3 is the magic number here, and this applies to any triangle of any shape.
Each matchstick is one side of the triangle. Having three of them forms the three sides. When you intersect any pair of sides, you form a vertex which is a corner point of the triangle. Each vertex corresponds directly to an interior angle.
Side note: the 3 interior angles of any triangle always add to 180 degrees.
