Math, asked by vishnu14, 1 year ago

angle bed=angle bde and e is the mid point of bc prove that af/cf=ad/be

Answers

Answered by kvnmurty
338
See diagram...  

Let 
∠BDE = ∠BED = x°.  
Hence, in ΔBDE, we have BD = BE = BC/2.

Now Draw CG parallel to AB.   
CEG = x°  (vertical angle). 

 ΔBED and Δ CEG are similar as   CE || BE, CG || BD, EG || ED.
Since BE = EC, They are congruent.  
Hence, 
∠CEG = ∠CGE = x°   and    ∠ECG = ∠B.

Now for the ΔABC, 
∠FCB is external angle =>    ∠FCB = ∠A+∠B
Hence,   
∠GCF = ∠A.
Further, 
∠CGF = 180° - ∠CGE = 180° - x°.

In ΔCGF , 
∠F = 180° - ∠A - (180° - x°) = x° - ∠A

Now compare ΔADF  and  Δ CGF:  Since all corresponding angles are same they are similar triangles.

=>  AF/AD = CF/CG = CF / CE = CF / BE
=>  AF / CF = AD / BE
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Answered by pdroshni11
62

Here is you answer please refer the diagram too.

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