Find the equation of the line specified

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.

Aline passes through the points (5,4) and (2.1). part a.) what is the slope of the line that passes through these points? show work. part b.) what is the equation of the line that passes through these points. show work. part c.) where does the line intercept on the x& y axis? show work

There are four paths from the cabin to the lake. in how many ways can you walk from the cabin to the lake back?