In the given figure, if \(GE||CB\) and \(GF||CD\), prove that \(\frac{AE}{AB} = \frac{AF}{AD}\).
 
YCIND2402146037a15w1612_1.png
 
Proof:
 
In \(\Delta ACB\),
 
\(GE || CB\)
 
If a line is drawn parallel to one side of a triangle to intersect the other two sides in distinct points, the other two sides are divided in the same ratio.
 
\(\frac{AG}{GC} =\) ii - - - - (1)
 
In \(\Delta ACD\),
 
\(GF || CD\)
 
If a line is drawn parallel to one side of a triangle to intersect the other two sides in distinct points, the other two sides are divided in the same ratio.
 
\(\frac{AG}{GC} =\) ii- - - - (2)
 
From (1) and (2),
 
\(\frac{AE}{EB} = \) ii
 
\(\frac{EB}{AE} = \) ii
 
Adding \(1\) on both sides, we get
 
EB+iAM=FD+iAN
 
ii=ii
 
\(\frac{AE}{AB} = \frac{AF}{AD}\)
 
Hence proved.