Polygons Formula Sheet

Geometry · Axiom Academy

FORMULA SHEET Polygons Formula Sheet Essential formulas for quadrilaterals and polygons Special Quadrilateral Properties Regular Polygon Interior Angles Square = Rectangle + Rhombus — it has ALL the properties of both. To find n from an interior angle: Exterior = 180° − Interior, then n = 360° ÷ Exterior. Trapezoid midsegment is parallel to the bases and equals their average. Rhombus area uses the diagonals: half the product of the diagonals. Apothem is the perpendicular from the center to a side (used for regular-polygon area). Interior + Exterior = 180° at any vertex of any polygon.

This is the written version of the interactive lesson above. See the full Geometry course.