# Mid point theorem

In the attached figure D and E are respectively mid points of AB and AC. Given that DE parallel to BC. Prove that DE bisects AF, that is to prove that AO = OF. I want a proof not using the concept of similarity of triangles. Please help.

Note by Indulal Gopal
3 years, 3 months ago

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Since DE parallel BC therefore OE parallel FC . Now in triangle AFC , OE parallel FC ,and E is the mid point of AC , therefore O is the mid point of AC [ Converse of mid point theorem }

- 3 years, 3 months ago

In Triangle ABF D mid point of AB and DO//BF so O is mid point of AF

- 3 years, 3 months ago

Try it using sine law or you can also do it by area of triangles.See if this helps . i will post whole solution later. EDIT: Oh i thought we have to prove mid point theorem. You can prove it by converse of mid point theorem

- 3 years, 3 months ago