If you teach yourself in advance, you can use trigonometry or similar triangles (this is the content of grade three), which is relatively simple.

If you don't learn, let CD be x, and then use Pythagorean theorem be 2+de 2 = db 2.

Then bring x in and work it out (actually, it's okay, it's not very complicated! )

The answer from both methods is 12/5(2.4).

16, angle ACO=45 degrees, angle OEC = 90 degrees, so OE=CE.

And because they are all bisectors, there are CE=CD, BD=BF, AE=AF.

Let CE=a, BD=b and AE=c respectively.

List equations

A+b=8, a+c=6, b+c= 10 (this equation group is not difficult to solve, just add it all up and subtract it).

The solution is a=2.

The answer you want is 2.