Question

Draw lines AE=AB=BC=5cm and <BAE=<ABC=108°.Wid C and E as centres and radius 5cm,draw ares to intersect @ D and F.Join ,CD,DE,EF and FC.What type of quadrilateral is CDEF?What is the area of CDEF??Plz heeeeelp?????

Answer 1

I think you can show with little effort that CDEF is a parallelogram.

Then find angle θ=DEF of CDEF and its area is 5*5*sinθ