Question

what is Bpt & Thales theorem?

Answer 1

Basic Proportionality Theorem (Thales theorem): If a line is drawn parallel to one side of a triangle intersecting other two sides, then it divides the two sides in the same ratio.

Answer 2

Basic Proportionality Theorem (Thales theorem):If a line is drawn parallel to one side of a triangle intersecting other two sides, then it divides the two sides in the same ratio. 

In ∆ABC , if DE || BC and intersects AB in D and AC in E then 
    AD       AE
   ---- = ------
    DB      EC

Proof on Thales theorem :

If a line is drawn parallel to one side of a triangle and it intersects the other two sides at two distinct points then it divides the two sides in the same ratio.