Caca pipipoopoo checkkkkkkkk
Answer:
12.686cm
Step-by-step explanation:
By using pythagoras, we can find CB.
We know that 
Therefore, 
(it has to be positive since it is distance)
now we look at triangle BCD and use SOH CAH TOA.

( x-5 ) (x + 6 )
multiply
X times X + 6x - 5x - 5 times 6
connect like terms
x squared + 6x - 5x - 30
Answer is
x squared + x - 30