Dependent angle CDE= angle BAF

So angle EDA= angle DAB

So DE//AB (internal dislocation angle)

(2)。 In quadrilateral ABCD and quadrilateral ADEF

Angle CDA+ Angle DAB= Angle EDA+ Angle DAF

So angle C+ angle B= angle E+ angle f.

Therefore: 124+90 = 80+ angle f.

Angle f = 134.