Ah, what a lovely question! The shape you're thinking of is a triangle. Triangles have three straight sides and no right angles. They come in all different sizes and can be found in nature and in art. Just imagine all the beautiful landscapes you could create with triangles!
A shape that has four straight sides and four angles is defined as a quadrilateral. If all four angles are right angles, it is a rectangle, and if all four sides are congruent, it is a square.
A shape with parallel sides but no right angles is called a parallelogram
A RECTANGLE has 4 sides and 4 right angles.
Squares and rectangles have a two-dimensional shape with four sides and four right angles.
A rhombus has four equal sides but no right angles.
square
hexagon and octagon.
a Rhombus...
A rhombus is one of them
A rectangle book has a rectangular shape, with four straight sides and four right angles.
A shape that has four straight sides and four angles is defined as a quadrilateral. If all four angles are right angles, it is a rectangle, and if all four sides are congruent, it is a square.
A shape with five sides would be a pentagon, but a shape can not have 5 right angles. Squares and Rectangles are both shapes with 4 sides and 4 right angles. They are the only shape with the same amount of right angles as there is sides.
A shape with parallel sides but no right angles is called a parallelogram
A straight line
A RECTANGLE has 4 sides and 4 right angles.
This shape has only one pair of opposite sides and no right angles: <
If there are no angles, all you have is a 'straight side'. There is a plane and no shape. Maybe you are thinking that straight means standing up straight. You might then be thinking of an upright tube.