Download Using these formulas in reverse (algebra is your

Geometry
5.1 Notes - Polygon Angle Sum
Name___________________________ Per___
There are some polygon interior angle sums you probably already know…
Triangle Angle Sum = _________
Quadrilateral Angle Sum = ________
Pentagon Angle Sum = _______
But what about interior angle sums of larger polygons? Use the Triangle Method!
TASK: Complete the table below. Look for a pattern in your results and try to find an angle-sum formula for any n-gon.
FORMULA: Angle sum for any polygon with n sides = ________________________
Suppose we have an equiangular polygon, as seen below. How can we find the measure of ONE interior angle?
FORMULA: One interior angle of a regular polygon with n sides = ____________________________
Using these formulas in reverse (algebra is your friend).
EXAMPLE 1: How many sides does a polygon have if the sum of its angles measures is 5220°?
EXAMPLE 2: How many sides does an equiangular polygon have if each interior angle measures 165°?