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In the given figure, if AB || CD || FE then find x and AE. - Geometry Mathematics 2

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Question

In the given figure, if AB || CD || FE then find x and AE. 

Sum

Solution 1

Construction: Join AF intersecting CD at X.

In ΔABF, DX || AB 

`"FD"/"DB"="FX"/"XA"`  ...(1) (By Basic proportionality theorem)

In ΔAEF, XC || FE 

`"FX"/"XA"="EC"/"CA"` ... (2) (By Basic proportionality theorem)

From (1) and (2), we get 

`"FD"/"DB"="EC"/"CA"`

`4/8 = x/12`

x = 6 

Now, AE = AC + CE

= 12 + 6

= 18

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Solution 2

line AB || line CD || line FE   ...(given)

∴ `("BD")/("DF") = ("AC")/("CE")`   ...(Property of three parallel lines and their transversals)

∴ `8/4 = 12/x`

∴ x = `(12 xx 4)/8`

∴ x = 6 units

Now, AE = AC + CE [A - C - E]

= 12 + x

= 12 + 6

= 18 units

∴ x = 6 units and AE = 18 units

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Notes

Students can refer to the provided solutions based on their preferred marks.

Property of an Angle Bisector of a Triangle
  Is there an error in this question or solution?
Chapter 1: Similarity - Practice Set 1.2 [Page 14]

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solution:

In ∆PMQ,

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∴ XY || QR   .............[Converse of basic proportionality theorem]


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