Find the answer for me please (circumference)

What is the vertex form of f(x) = x2 + 6x + 3

When you are making a circle graph by hand, how do you convert a number for a part into its corresponding angle measure in the circle graph? when you are making a circle graph by hand, what should you do if one of your angle measures is greater than 180°?

Acar travels at an average speed of 56 miles per hour. how long does it take to travel 196 miles