Explain how the estimating the quotient you place the first digit in the quotient of a division

If the value of cos330°is√3/2 then find cos 165°.

Find measure angle 1 and measure angle 3 in the kite the diagram is not drawn on the scale

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?