As shown in Figure 5, point C is the point on line AB, point m is the midpoint of line AC, and point n is the midpoint of line BC. (2) AC: CB = 3:2, Mn = 10cm, Find the length of am A----M----C--N--B

As shown in Figure 5, point C is the point on line AB, point m is the midpoint of line AC, and point n is the midpoint of line BC. (2) AC: CB = 3:2, Mn = 10cm, Find the length of am A----M----C--N--B

∵ m is the midpoint of AC, n is the midpoint of BC, Mn = 10cm
∴2MN=AC+BC=2*10cm=20cm
And ∵ AC: CB = 3:2
∴AC=20÷(3+2)*3=12cm
And ∵ m is the midpoint of AC
∴AM=1/2AC=12÷2=6cm