數學問題1條~~~~~~~~~~~~~!!!!!有圖!!!!!10分!

1a:
AB=AE=AF=FE (given)/(sides of ragular polygon)
so AB=AF,CB=FE
angleABC = angleAFE = [180x(6-2)]/6 = 120 (angle of ragular polygon)
so, angleABC = angleAFE
so, triangleABC = triangleAFE (SAS)

1b:
(use the same method in 1a to prove that triangleABC = triangleAFE = triangleCDE)
as triangleABC = triangleAFE = triangleCDE
so, AC = CE = AE (sides of congruent triangles)
as AC = CE = AE
so, triangle ACE is equilateral (3 sides equal)

1a ) angle ABC and angle AFE is equal (120 degree.....720_angle sum of polygon_/6)
the sides AB, BC, AF, FE are equal (regular hexagon)
So, triangle ABC is congruent to triangle AFE (S.A.S.)

1b ) because triangle ABC is congruent to triangle AFE and triangle CDE ,
that means the base sides of them are equal, equals to "AC = AE = CE ",
thus, triangle ACE is equilateral.