Answer:
BE = 3.5 m
Step-by-step explanation:
Δ ACB and Δ EDB are similar, so the ratios of corresponding sides are equal, that is
[tex]\frac{BE}{BA}[/tex] = [tex]\frac{BD}{BC}[/tex] , substitute values
[tex]\frac{BE}{21}[/tex] = [tex]\frac{3}{18}[/tex] ( cross- multiply )
18 BE = 63 ( divide both sides by 18 )
BE = 3.5
