Inradius
The inradius of a polygon is the radius of its incircle (assuming an incircle exists). It is commonly denoted .
Properties
- If has inradius and semi-perimeter , then the area of is . This formula holds true for other polygons if the incircle exists.
Problems
- Verify the inequality .
- Verify the identity (see Carnot's Theorem).
- 2007 AIME II Problems/Problem 15
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