The triangles AEC and BFD are similar because of AA similarity postulate.
Angles C and D are congruent
Angles E and F are congruent so are
Obs:
Angles A and B since the sum of all angles in any triangle is 180 degrees.
If the triangles are their sides are in proportion.
BD/AC= DF/CE so
BD/6= (6+2)/(6+4)
BD= 6•8/10=4.8
Answer B) BD=4.8
