The Quadrilaterals ClipArt gallery offers 93 illustrations of a variety of closed two-dimensional geometric figures with four sides. The most common quadrilaterals are squares, rectangles, parallelograms, and trapezoids. Images include examples of concentric and inscribed quadrilaterals.

"From Figure 4 he sees a parallelogram equal to a rectangle of the same base and altitude. Cut out and…

"The student sees the trapezoid is equal in area to a rectangle whose base is the average base of the…

"The student sees the trapezoid is equal in area to a rectangle whose base is the average base of the…

Illustration of a circle inside of 2 concentric rectangles whose vertices are connected by line segments.

Illustration of a parallelogram with diagonals AC and BD intersecting at point O.

A square divided into equal squares, like a chessboard, in each of which is placed one of a series of…

"In the diagram, let AB and AC represent two forces acting upon the point, A. Draw the two dotted lines…

Illustration of a parallelogram with altitude and diagonal drawn.

Illustration of parallelogram AEFC drawn two different ways with base b and altitude/height a used to…

Illustration of a parallelogram with diagonals drawn to show they bisect each other.

Parallelogram with dimensions labeled. Parallelogram can be used to calculate area.

Parallelogram with dimensions labeled. Parallelogram can be used to calculate area.

Illustration to show that when lines from two opposite vertices of a parallelogram to the midpoints…

Parallelogram with dimensions drawn to show relationship to the area of a rectangle.

Illustration of a two equal parallelograms. Two parallelograms are equal, if two sides and the included…

Illustration of a two polygons. Polygons may be mutually equiangular without being mutually equilateral.

Illustration of two polygons. Polygons may be mutually equilateral without being mutually equiangular…

Quadrilateral with intersecting diagonals and segment connecting midpoints.

Illustration of an axis of symmetry drawn with respect to a quadrilateral.

Illustration to show that if the diagonals of a quadrilateral bisect each other, the figure is a parallelogram.

Illustrations to show quadrilaterals with lines joining the midpoints of the sides of any quadrilateral,…

Illustration of a quadrilateral which has two adjacent sides equal and the other two sides equal. It…

A quadrilateral plane figure having four right angles and its opposite sides equal in length. The adjacent…

Illustration of a circle inside of a rectangle. The two figures have the same center.

Illustration to show that if the diagonals of a parallelogram are equal, the figure is a rectangle.

Rectangle with dimensions labeled. Rectangle can be used to calculate area.

Illustrations to show that if two parallel lines are cut by a transversal, the bisectors of the interior…

An illustration of a rectangle with lengths a and b and area ab.

An illustration of composite rectangle with lengths a, b, and c with area ac + bc. This illustration…

A rhomboid is a parallelogam whose opposite sides are equal, and whose angles are not right angles.

This 24x24 square shows how square root can be taught. It is divided up into 4x4 and 20x20.

Illustration of a square constructed upon the sum of two straight lines.

Illustration of a square constructed upon the difference of two straight lines.

Illustration of a square constructed upon the difference of two straight lines.