a closed plane figure with all sides congruent and all all angles
That could be numerous polygons: a square, a regular hexagon, a regular octagon, a regular dodecagon ... Any regular polygon with an even number of sides could be your answer.
Not always because a quadrilateral is any 4 sided shape.
That's a rhombus ... a special type of parallelogram.
That's a rhombus ... a special type of parallelogram.
Opposite sides are parallel, Consecutive angles are supplementary, Opposite angles are congruent, Opposite sides are congruent (APEX)
A quadrilateral is a four-sided polygon (closed shape made with line segments). Quadrilaterals have four angles (vertices) and come in many different shapes, depending on the length of their sides and the kinds of angles they have. The five most common quadrilaterals are the rectangle, square, parallelogram, rhombus, and trapezoid. A rectangle is a quadrilateral with opposite sides congruent (same length) and parallel. It has four right (90º) angles. A square has ALL four sides that are congruent, and two pairs of parallel sides. It also has four right angles. A parallelogram has two pairs of parallel sides. They form two acute and two obtuse angles. A rhombus has two pairs of parallel sides, but all sides are congruent. They also form two acute and two obtuse angles. Finally, a trapezoid, has only one pair of parallel sides. The parallel sides are NOT congruent. A trapezoid can be formed by two acute and two obtuse angles, or by two right angles, one acute, and one obtuse angle.
A rectangle has four sides and four angles. A rectangle is a closed shape. All four angles of a rectangle are right angles. That is, they are 90 degrees. Opposite sides of a rectangle are the same length. Opposite sides of a rectangle are parallel. That is, if they were extended infinitely they wouldn't touch. ***Additionally, the diagonals of a rectangle are congruent (unlike other parallelograms), and they also bisect each other. While all parallelograms share the bisecting diagonals characteristic, only rectangles (and by extension squares) have congruent diagonals.***
A quadrilateral is ANY closed figure with 4 sides. Therefore, it also has 4 angles - any of which may, or may not, be congruent. About the only general statement about angles that applies to all quadrilaterals is that the sum of the angles is 360 degrees. By the way, it is possible for a quadrilateral to have 3 congruent angles, and the fourth angle not be congruent with the other 3.
Cjic
a closed plane figure with all sides congruent and all all angles
It is a regular polygon.
That could be numerous polygons: a square, a regular hexagon, a regular octagon, a regular dodecagon ... Any regular polygon with an even number of sides could be your answer.
Not always because a quadrilateral is any 4 sided shape.
That's a rhombus ... a special type of parallelogram.
That's a rhombus ... a special type of parallelogram.
A closed planar figure with four right angles. This makes opposite sides parallel and of equal length and of course adjacent sides "normal" to each other ('normal' in geometry means at right angles). There is an inside and an outside. The center of gravity lies at the intersection of the diagonals and the intersection of the lines connecting opposite midpoints.