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Overview
Geometry, Measurement and Finance 10
Geometry
11. Demonstrate an understanding of angles, including acute, right, obtuse, straight and reflex
11.6 Complex polygons
Complex Polygons: Concave vs Convex Polygons
Discover what makes a polygon concave, convex, or irregular, and learn a reliable method for finding the area of any complex polygon.
What You'll Learn
Identify a convex polygon by checking that every interior angle is less than 180 degrees
Recognize a concave polygon by spotting at least one reflex angle greater than 180 degrees
Compare concave pentagons, hexagons, and octagons using the same reflex-angle test regardless of side count
Apply triangle decomposition to calculate the area of an irregular or concave polygon
Subtract the area of a reflex notch when a diagonal of a concave shape falls outside the figure
Calculate total area by summing or subtracting the areas of simple shapes that make up a complex polygon
This Unit Includes
Learning resources
NB Curriculum Aligned