octagon
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.
a square
no shape does! * * * * * Not true. A parallelogram has rotational symmetry of order 2, but no lines of symmetry.
An irregular heptagon, also known as a seven-sided polygon, may have zero, one, or more lines of symmetry depending on its specific shape. In general, a heptagon can have up to seven lines of symmetry if it is a regular heptagon with all sides and angles equal. However, irregular heptagons have varying side lengths and angles, which can result in different numbers of lines of symmetry. To determine the exact number of lines of symmetry for a specific irregular heptagon, you would need to analyze its unique characteristics and geometric properties.
Pentagon
Square
There is no such shape. A 2d shape with 5 sides and all equal angles must be a regular pentagon (or a 5-pointed star if you stretch the definition of "all angles"). And a regular pentagon - or star - has 5 lines of symmetry.
octagon
Impossible.
An irregular quadrilateral.
The shape that has three lines of symmetry is the equilateral triangle. It also has three angles of equal size and three sides of equal length.
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.
rhombus
a square
7
square and rectangles are technicality squares