SOLUTION: the measure a of an interior angel of a fegular polygon with n sides is given by the formula a= 180 [1- 2/n ] solve formula for n. how many sides does a regular polygon have if an

Algebra ->  Percentages: Solvers, Trainers, Word Problems and pie charts -> SOLUTION: the measure a of an interior angel of a fegular polygon with n sides is given by the formula a= 180 [1- 2/n ] solve formula for n. how many sides does a regular polygon have if an      Log On


   

Question 357318: the measure a of an interior angel of a fegular polygon with n sides is given by the formula a= 180 [1- 2/n ] solve formula for n. how many sides does a regular polygon have if an interior angel is 140
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
A = 140 = 180(1 - 2/n)
140 = 180 - 360/n
140n = 180n - 360
40n = 360
n = 9
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Get the exterior angle, = 180-140 = 40
The sum of exterior angles for ALL polygons = 360
360/40 = 9