given to us is the triangles are similar:
- DEC is Isosceles (due to DC= EC)
- AB || DE
this means the ratios of the sides of the 2 triangles will be the same for all sides
we already have DE, so we need to figure out either DC or EC
(1) BE is 5/7 of BC
while this lets us calculate the ratio, it doesn't tell us anying about the lengtof either of the 2 unknown legs on which we can apply those ratios to try and calculate EC (which we could have done with either the length of BE or BC)
Not suff.
(2)
...
- DEC is Isosceles (due to DC= EC)
- AB || DE
this means the ratios of the sides of the 2 triangles will be the same for all sides
we already have DE, so we need to figure out either DC or EC
(1) BE is 5/7 of BC
while this lets us calculate the ratio, it doesn't tell us anying about the lengtof either of the 2 unknown legs on which we can apply those ratios to try and calculate EC (which we could have done with either the length of BE or BC)
Not suff.
(2)
...
