Question

prove that sum of all angles of a parallelogram is 360

Answer 1

generally  sum of all outer angles of any polygon is 360
       also the sum of all interior angles of parallelogram is
                      = 180(n-2) n is no of sides
                      = 180 (4-2)
                            =  360
      so each interior angles will have 360 / 4
                            = 90
and interior angles and exterior angles form linear angle
                 180= exterior angle+ interior angle
                  180 =  x + 90
             180 - 90 = x
                     90 = x
             so all other exterior angle will 90
                    90 * 4 = 360
              so hence it is proove