A5 dimensions in inches

How to Calculate the Sum of Interior AnglesA polygon is any closed figure with sides made from straight lines. At each vertex of a polygon, there is both an interior and exterior angle, corresponding to the angles on the inside and outside of the closed figure. Understanding the relationships that govern these angles is useful in various geometrical problems. In particular, it is helpful to know how to calculate the sum ofinterior angles in a polygon. This can be done using a simple formula.Exterior angleInterior angleHexagon = 6 sides1.Count the number of sides your polygon has.The method for calculating the sum of interior angles is based on how many sides the polygon has. Remember that a polygon must have at least 3 sides (a triangle), and each side must be a straight line. Hexagon = 6 sides6 –2 = 42.Subtract 2 from the number of sides.For example, subtracting 2 from a triangle gives you the number 1. Subtracting 2 from a pentagon (which has 5 sides) gives you the number 3. Subtracting 2 from a hexagon (which has 6 sides) gives you the number 4.
4Hexagon = 6 sides36 –2 = 4124x 180º= 720ºNotice that there are 4 trianglesand remember that the sum of each triangle measures 180ºThis is why this formula works!3.Multiply this number by 180.Multiply the number arrived at in the previous step(4)by 180. This will give youthe sum of the polygon's interior angles, expressed in degrees. For example, consider thishexagon. Subtracting 2 from a hexagon's 6 sides equals4. Multiplying 4 by 180 equals720. Therefore, a hexagon (regular or irregular-that means the polygons don’t have to have equal sides or angles for this to work) has interior angles that add up to 720 degrees. Because this hexagon IS a regular polygon, you could then divide by the number of interior angles to find out what each angle measures.4.Review the formula used to calculate this sum.Building a formula from the steps above yields: s = 180(n -2), where "s" is the sum of the interior angles and "n" is the polygon's number of sides. This formula can be used for a polygon with any number of sides.