Abcd is a trapezium in which ab is parallel to dc, bd is a diagonal and e is the mid point of ad a line is drawn through e parallel to ab intersecting bc at f show that f is the mid point of bc

F is the mid point of BC. (Proved)

Step-by-step explanation:

See the attached diagram.

Given AB ║ CD and EF is drawn to be parallel to AB.

So, EF ║ AB ║ CD .......... (1)

Now, in Δ ABD, E is the midpoint of AD and EG is parallel to AB.

So, G must be the midpoint of BD.

Now, in Δ BCD, G is the midpoint of DB and GF is parallel to CD. {From relation (1)}

So, we can write F is the midpoint of BC. (Proved)

[Since we know the theorem that if we joint the midpoints of two sides of a triangle then the line formed will be parallel to the third side.]