Since the variable x has an invisible one next to it, which is 1x, it is 6x.
Answer:
DC = 3
Step-by-step explanation:
Based on triangle similarity theorem, we would have the following equation:

Plug in the values



Cross multiply
3(9 + DC) = 9×4
27 + 3DC = 36
Subtract 27 from each side
3DC = 36 - 27
3DC = 9
Divide both sides by 3
DC = 9/3
DC = 3
If I did this correctly all you hade to do is work in reverse.
1.) Divide 16 by pi (3.14) To get the diameter.16/ 3.14 =5.095541401 or 5.1
2.) Since Diameter is just the radius doubled divide 5.1 by 2. 5.1 /2 = 2.55
3.) Plug it in, use the 2pir equation to see if it works. 2X3.14X2.55= 16.014 or 16.
I hope this helps, let me know if you need further explanation.