Answer:
LN = 66 cm
Step-by-step explanation:
The 3 parallel lines divide the 2 sides they intersect in proportion, that is
[tex]\frac{DE}{EF}[/tex] = [tex]\frac{LM}{MN}[/tex] , substitute values
[tex]\frac{7}{15}[/tex] = [tex]\frac{LM}{45}[/tex] ( cross- multiply )
15LM = 315 ( divide both sides by 15 )
LM = 21
Hence
LN = LM + MN = 21 + 45 = 66 cm
