a pentagon
A rectangle. Obviously the right angles are in the four corners of the rectangle. The lines of symmetry occur across the horizontal and vertical. There are no lines of symmetry on the diagonal.
Well, isn't that just a delightful shape you've described! A figure with 5 lines of symmetry and no right angles is called a pentagon. It has those lovely symmetrical qualities that make it so pleasing to the eye. Just imagine all the wonderful ways you could paint and create with such a shape!
A rectangle.
A pentagon has 5 lines of symmetry and no right angle.
octagon
If your asking what shape has three lines of symmetry, your answer would be an equilateral triangle. You can tell how many lines of symmetry a shape that has all angles of the same measure has by looking at it's angles. Ex., pentagon has five angles--five lines of symmetry; octagon has eight angles, eight lines of symmetry; etc.
An irregular quadrilateral.
rhombus
a square
A rectangle.
The shape you are describing is a trapezoid. A trapezoid is a quadrilateral with at least one pair of parallel sides. It can have two right angles, but it does not have any lines of symmetry due to its asymmetrical nature.