A four-sided shape is a quadrilateral. With only one pair of parallel sides, it would be called a trapezoid (UK trapezium).
Such a figure is called a parallelogram.
Whether or not the opposing angles of a trapezoid (UK trapezium) are equal depends on the axis of symmetry. A trapezoid (trapezium) can be defined as a quadrilateral with one pair of opposite sides parallel. It is not a parallelogram because only one pair of sides is parallel. It is called a regular trapezoid if the sides that aren't parallel are equal in length and both angles coming from a parallel side are equal
A kite is a quadrilateral, called a deltoid. Among its four sides, there is one line of symmetry. Two sets of adjacent sides across the line of symmetry are the same length. One set of opposite angles is congruent. The diagonals of kites form 90° angles.
Congruent
It is called a square.
A square or a rhombus
There is no special name.
that quadrilateral would be called a trapezoid. :)
parallelogram
A four-sided shape is a quadrilateral. With only one pair of parallel sides, it would be called a trapezoid (UK trapezium).
That is called a parallelogram. Parallelogram includes squares, rectangles, and rhomboids.
It is called a parallelogram.
Such a figure is called a parallelogram.
parallelogram
rectangle, square, rhombus
That is called a rectangle.