A regular polygon has an angle of size 160 each. How many sides does the polygon have

Aword processing program requires a 7- digit registration code made up of the digits 1,2,4,5,6,7 and 9 each number has to be used and no number can be used mor than once how many codes are possible

Which is the focus of a parabola with equation y2=4x

Either enter an exact answer in terms of \piπ or use 3.143.14 for \piπ and enter your answer as a decimal.