Parallelogram and a rectangle
Is rectangle and any parallelogram not square or rhombus
true
Yes.
The answer would be a right cylinder. A right cylinder is a cylinder that has a closed circular surface having two parallel bases on both the ends and whose elements are perpendicular to its base.
It could be a trapezoid
They could be: parallel lines, perpendicular lines or intersecting lines
If you are sitting in a room, the ceiling and the floor are parallel to each other. The walls are perpendicular to the floor and to the ceiling. So any line on these surfaces will be parallel to or perpendicular to any line on the other surface. And if they were not, the building could be quite unstable.
4sides
Using the term "trajectory" implies that the acceleration you are concerned about is due to gravity. Gravity will always be perpendicular to the surface. Unless the trajectory begins perpendicular to the surface, it will never change to become perpendicular and the velocity will never be in a direction parallel to the acceleration. If it starts perpendicular to the surface it will start and remain perpendicular. Of course if you have another force acting on the object - such as wind - the component of the velocity vector parallel to the ground could be reduced to zero and at that point the only remaining component of the velocity vector would be that perpendicular to the ground and parallel to the acceleration. Likewise if the object is being propelled by an engine or rocket, the trajectory could be parallel to the force any time the acceleration vector became parallel to the velocity vector.
Parallelogram and a rectangle
It's not quite clear what's your question is actually asking but in general squares and rectangles consist of parallel and perpendicular line whereas right angle triangles have only perpendicular lines which meet at 90 degrees.
If the field lines were not perpendicular to the surface, then they could be decomposed into components perpendicular and parallel to the surface. But if there is an E-field along the surface, the surface is no longer an equipotential.
Two lines are said to be parallel if perpendicular distance between them is always constant. Length of a pair of parallel lines need not to be same. It can be different.
It could be a right angle triangle
Parallelogram and a rectangle
It could be a square or a rectangle