Answer:

a.         Shape                                          Formula  

   3 sided polygon (triangle)            (3−2)⋅180

   4 sided polygon (quadrilateral)   (4−2)⋅180

   6 sided polygon (hexagon)         (6−2)⋅180

b. To find the angle of any regular polygon you find the number of sides , which in this example is . You then subtract from the number of sides yielding . Take and multiply it by degrees to yield a total number of degrees in the regular nonagon. Then to find one individual angle we divide by the total number of angles

Hope this helps!