Answer:
6.7
Step-by-step explanation:
Here, we can apply cosine law, 
We the plug in values: 
and solve that CB is around 6.7
These numbers from least to greatest would be: 4.72, 4.74, 4.98
This is actually quiet easy!
(23.80/140) x 100 = (0.17) x 100 = 17%
That's how you do it! Hope this helps!