As shown in the figure, AC: CD: DB = 2:3:4, if e is the midpoint of AC, f is dB The distance between the midpoint, e and F is 5.4cm

The length of AB is 8.1 cm
Because AC: CD: DB = 2:3:4, let AC = 2x, CD = 3x, DB = 4x
Because EF = EC + CD + DF = 5.4, the solution of X + 3x + 2x = 5.4 is x = 0.9
9*0.9=8.1

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