Answer:
BC = 1 

Explanation:
since the triangles are similar then the ratios of corresponding sides are in proportion, that is
 =
 = 
 ( substitute values )
 ( substitute values )
 =
 = 
 ( 2
 ( 2 
 =
 = 
 )
 )
cross- multiply
 BC = 4 ×
 BC = 4 × 
 = 3 ( multiply both sides by 2 to clear the fraction )
 = 3 ( multiply both sides by 2 to clear the fraction )
5 BC = 6 ( divide both sides by 5 )
BC = 
 = 1
 = 1 
