Anybody know trigonometry well? message me if you do.

What is the approximate circumference of the circle shown below?

What is a rational number between 9.5 and 9.7

Long division setup showing an incomplete calculation. 12 is in the divisor, 6839 is in the dividend, and 5 hundreds and 6 tens is written in the quotient. 6000 is subtracted from 6839 to give 839. an unknown value represented by a box is being subtracted from 839. what number should be placed in the box to complete the division calculation?