For which segment lengths is LN⎯⎯⎯⎯⎯ parallel to XY⎯⎯⎯⎯⎯ ?

For which segment lengths is LN⎯⎯⎯⎯⎯ parallel to XY⎯⎯⎯⎯⎯ ?
Select Parallel or Not parallel for each set of given information.
Segment lengths Parallel Not parallel
LX=2, XM=7, NY=4, YM=14 --- ----

LX=2, XM=6, NY=3, YM=9 --- -----

LX=2, XM=3, NY=4, YM=7 --- -----enter image source here

1 Answer
Jan 20, 2018

Case 1 : XY Parallel to LN

Case 2 : XY Parallel to LN

Case 3 : XY Not Parallel to LN

Explanation:

enter image source here
Hope you refer to the above figure

If XY & LN are parallel, then the two triangles MLN & MXY are similar.

#:. (ML) / (MX) = (MN) / (MY) = (LN) / (XY)#

#(MX + LX) / (MX) = (MY + NY) / (MY)#

#cancel(1) + (LX)/(MX) = cancel(1) + (NY) / (MY)#

#(LX) / (MX) = (NY) / (MY)#

Substituting the values

Case 1 :
Given #LX =/2, XM = 7, NY = 4, YM = 14#

#2/7 = 4/14 = 2/7# satisfies the condition that XY // to LN

Case 2 :
Given #LX = 2, XM = 6, NY = 3, YM = 9#

#2/6 = 3/9 = 1/3# satisfies the condition that XY // to LN

Case 3 :

Given #LX = 2, XM = 3, NY = 4, YM = 7#

#2/3 != 4/7# does not satisfy the similarity condition and hence

XY not // to LN