none
A regular pentagon has zero perpendicular sides. If it is irregular, it could have as many as 2 or 4 perpendicular sides.
A right angle has one pair of perpendicular sides.
2, the two smallest sides are perpendicular to eachother.
7
100
A regular pentagon has zero perpendicular sides. If it is irregular, it could have as many as 2 or 4 perpendicular sides.
An equilateral triangle doesn't have any perpendicular sides on it.
A rhombus has no perpendicular sides but its diagonals are perpendicular to each other and meet at right angles.
2, the two smallest sides are perpendicular to eachother.
A right angle has one pair of perpendicular sides.
7
100
24
none
8
Zero
Four