5
A regular pentagon has zero perpendicular sides. If it is irregular, it could have as many as 2 or 4 perpendicular sides.
2
None
It can have one or two.
A single side cannot be perpendicular on its own. Two sides are perpendicular if they intersect at a 90 degree angle. There are many polygons, both regular and irregular, that can have perpendicular sides.
None normally in a regular 5 sided pentagon but it is possible to construct an irregular pentagon with a pair of parallel sides.
A regular 5 sided pentagon has no perpendicular lines
There isn't really a good straight answer for that - if it's irregular, then it would completely depend on the hexagon...
count the corners! Penta=5, five sides=5 angles, five angles equal 5 intersections. Some of these may be perpendicular, but not necessarily.
A pentagon can have:none (regular or irregular pentagon)one, two or three right angles (irregular pentagon).
5
A decagon, which is a ten-sided polygon, can have a varying number of perpendicular sides depending on its specific shape. In a regular decagon, no sides are perpendicular to each other, as all angles are equal and measure 144 degrees. However, in irregular decagons, the number of perpendicular sides can vary. Therefore, the answer is that a decagon can have zero or more perpendicular sides, depending on its configuration.