Chengdu mc recruitment

Solution: As shown in the figure, ∵Ma' is a constant value. When the length of A'c is the smallest, that is, when A' is on MC,

With point m as MF⊥DC of point f,

∫ In a rhombic ABCD with a side length of 2, ∠ A = 60, and m is the midpoint of AD.

∴2MD=AD=CD=2,∠FDM=60，

∴∠FMD=30，

∴FD= 12MD= 12，

∴FM=DM×cos30 =32，

∴MC=FM2+CF2=7，

∴a′c=mc-ma′=7- 1.

So the answer is: 7- 1