Question

the parallelogram ABCD where is AB equal to 10 and BC equal to 6 the bisector of angle A meet DC at E AE and B C is produced intersect each other at F find the length of CF

Answer 1

here ABCD is a parallelogram where EC is equal to 5cm (mid point theorem where EcIs parallel and half of AB. so it is 5cm).
now consider triangle ADE and triangle ECF we should prove these two triangles are congruent.
DE =CE=5cm
angle ADE=ECF(alternate angles)
angle ADE=FEC(vertical opposite angles)
hence these two triangles are congruent
by cpct AD=CF.
which is equal to 6cm as AD=CF.