octagon
It is a trapezoid and its other 2 angles are obtuse and acute
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.
an equilateral triangle
no shape does! * * * * * Not true. A parallelogram has rotational symmetry of order 2, but no lines of symmetry.
a pentagon
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.
Parrallelogram (it has rotational symmetry but no lines of symmetry)
square and rectangles are technicality squares
Rectangle