4
Yes,I think it has got one
Oh, dude, a heptagon has like a bazillion pairs of perpendicular lines... just kidding! It actually has 14 pairs of perpendicular lines. So, like, if you ever need to find perpendicular lines in a heptagon, you've got plenty to choose from.
A square has four perpendicular sides.
At least two pairs: they form the outer rectangle which represents the "universe".
An octahedron is a closed 3-d shape with 8 polygonal faces. There are 257 topologically different convex octahedra. The number of perpendicular faces will depend on which particular octahedron you have in mind. The heptagon-based pyramid, for example, has none.
There are 257 topologically different convex octahedra. Many of these will have no parallel faces. It can have four pairs of parallel faces.
two.
An octahedron has 7 perpendicular lines.
a octahedron has 8 faces
7
Each lateral face is perpendicular to its lateral neighbours so that makes 4 pairs. In addition, opposite lateral faces may be perpendicular, making 6 pairs in all.
A truncated octahedron has 14 faces.
1 at the base
A triangular pyramid has four faces and 2 pairs.
A pentagonal prism has only 7 faces. Each of the five lateral faces is perpendicular to the two bases: that makes 10 pairs of mutually perpendicular faces. In general, the lateral faces are not perpendicular, but four of them may be perpendicular to one or more of its neighbors - at most 4 more pairs. Still not 25!
An octahedron has 8 sides.An octahedron is a polyhedron with eight plane faces.