1 Let the intersection of line segment AC and line segment FD be G point, then < agd = <; FGC (Equal Vertex Angle)

Because △AEC can coincide with △ABD after rotation, and AE = AB and AC = AD.

So BD=CE

So < ADB = & lt(American Cinema Editors) American Film and Television Editors Association.

So < DFC = < computer aided design.

Because △ACD is an equilateral triangle

So < CAD=60 degrees.

So < DFC=60 degrees.

2. Because the square, BC=DC and triangle ADE are all equal to triangle ABG, BG=DE, so BC-BG=DC-DE, that is, CG=CE.

(2) △AEF is an isosceles right triangle. Because △ADE≌ABF, angle FAE = ≌ BAE+≌ Fab = 90 and AF=AE because angle BAD = 90 (quadrilateral ABCD is a square).

So △AEF is an isosceles right triangle.

(3) ∠ DAE = ∠ GAE = ∠ Bag = ∠ Fab = 30 because AE shares ∠DAG equally.

△AFG is an equilateral triangle, then DE+BG=FB+BG=FG=AE=AF=AG.