If all of the angles of a hexagon are congruent, then what is the measure of each angle?

The answer is 120 degrees 
if you divide a hexagon into 6 equilateral triangles, the bottom angles will be 60 degrees but considering that the triangle will be next to another one, you will have to account for the 60 degrees on the adjacent triangle, so itll be 60 +60 degrees which is equal to 120 degrees

Distributive property

I’m pretty sure the slope would be 1 since the x and y values increase by 1