Illustration of a quadrilateral which has two adjacent sides equal and the other two sides equal. It is symmetrical with respect to the diagonal joining the vertices of the angles formed by the equal sides, and the diagonals are perpendicular to each other.

Quadrilateral with Symmetry

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

Illustration of a rectangle, which is a parallelogram with all angles right angles.

Rectangle

Illustration of a rectangle, which is a parallelogram with all angles right angles.

Illustration of a rhomboid, which is a parallelogram which has its angles oblique angles.

Rhomboid

Illustration of a rhomboid, which is a parallelogram which has its angles oblique angles.

Illustration of a rhombus, which is a rhomboid with all sides equal.

Rhombus

Illustration of a rhombus, which is a rhomboid with all sides equal.

Four roses.

Four Roses

Four roses.

Bilingual Counting Card featuring illustrations of four Sailfishes.

Bilingual Sailfish Counting Card 4

Bilingual Counting Card featuring illustrations of four Sailfishes.

English Counting Card featuring illustrations of four Sailfishes.

English Sailfish Counting Card 4

English Counting Card featuring illustrations of four Sailfishes.

Spanish Counting Card featuring illustrations of four Sailfishes.

Spanish Sailfish Counting Card 4

Spanish Counting Card featuring illustrations of four Sailfishes.

Bilingual Counting Card featuring illustrations of four Sandcastles.

Bilingual Sandcastle Counting Card 4

Bilingual Counting Card featuring illustrations of four Sandcastles.

English Counting Card featuring illustrations of four Sandcastles.

English Sandcastle Counting Card 4

English Counting Card featuring illustrations of four Sandcastles.

Spanish Counting Card featuring illustrations of four Sandcastles.

Spanish Sandcastle Counting Card 4

Spanish Counting Card featuring illustrations of four Sandcastles.

An orthographic illustration of a die displaying sides 1, 2, and 4.

Die with sides 01, 02, 04

An orthographic illustration of a die displaying sides 1, 2, and 4.

An orthographic illustration of a die displaying sides 1, 4, and 5.

Die with sides 01, 04, 05

An orthographic illustration of a die displaying sides 1, 4, and 5.

An orthographic illustration of a die displaying sides 2, 4, and 1.

Die with sides 02, 04, 01

An orthographic illustration of a die displaying sides 2, 4, and 1.

An orthographic illustration of a die displaying sides 2, 6, and 4.

Die with sides 02, 06, 04

An orthographic illustration of a die displaying sides 2, 6, and 4.

An orthographic illustration of a die displaying sides 4, 1, and 2.

Die with sides 04, 01, 02

An orthographic illustration of a die displaying sides 4, 1, and 2.

An orthographic illustration of a die displaying sides 4, 2, and 6.

Die with sides 04, 02, 06

An orthographic illustration of a die displaying sides 4, 2, and 6.

An orthographic illustration of a die displaying sides 4, 5, and 1.

Die with sides 04, 05, 01

An orthographic illustration of a die displaying sides 4, 5, and 1.

An orthographic illustration of a die displaying sides 4, 6, and 5.

Die with sides 04, 06, 05

An orthographic illustration of a die displaying sides 4, 6, and 5.

An orthographic illustration of a die displaying sides 5, 1, and 4.

Die with sides 05, 01, 04

An orthographic illustration of a die displaying sides 5, 1, and 4.

An orthographic illustration of a die displaying sides 5, 4, and 6.

Die with sides 05, 04, 06

An orthographic illustration of a die displaying sides 5, 4, and 6.

An orthographic illustration of a die displaying sides 6, 4, and 2.

Die with sides 06, 04, 02

An orthographic illustration of a die displaying sides 6, 4, and 2.

An orthographic illustration of a die displaying sides 6, 5, and 4.

Die with sides 06, 05, 04

An orthographic illustration of a die displaying sides 6, 5, and 4.

Signal for the letter D, or the number four.

Signal D

Signal for the letter D, or the number four.

Probability Spinner 4

Spinner

Probability Spinner 4

Bilingual Counting Card featuring illustrations of four Sponge Divers.

Bilingual Sponge Diver Counting Card 4

Bilingual Counting Card featuring illustrations of four Sponge Divers.

English Counting Card featuring illustrations of four Sponge Divers.

English Sponge Diver Counting Card 4

English Counting Card featuring illustrations of four Sponge Divers.

Spanish Counting Card featuring illustrations of four Sponge Divers.

Spanish Sponge Diver Counting Card 4

Spanish Counting Card featuring illustrations of four Sponge Divers.

Illustration of a square, a rectangle with all sides equal.

Square

Illustration of a square, a rectangle with all sides equal.

4 pointed star

Star

4 pointed star

Bilingual Counting Card featuring illustrations of four Starfishes.

Bilingual Starfish Counting Card 4

Bilingual Counting Card featuring illustrations of four Starfishes.

English Counting Card featuring illustrations of four Starfishes.

English Starfish Counting Card 4

English Counting Card featuring illustrations of four Starfishes.

Spanish Counting Card featuring illustrations of four Starfishes.

Spanish Starfish Counting Card 4

Spanish Counting Card featuring illustrations of four Starfishes.

An illustration of a three person file military formation.

Three Person File Military Formation

An illustration of a three person file military formation.

Illustration of a trapezium, a quadrilateral which has no two sides parallel.

Trapezium

Illustration of a trapezium, a quadrilateral which has no two sides parallel.

Illustration of a trapezoid, a quadrilateral which has two and only two sides parallel.

Trapezoid

Illustration of a trapezoid, a quadrilateral which has two and only two sides parallel.

Illustration of a trapezoid, with the median drawn. The median of a trapezoid is parallel to the bases, and is equal to half the sum of the bases.

Trapezoid With Median

Illustration of a trapezoid, with the median drawn. The median of a trapezoid is parallel to the bases,…

An illustration of a two person file military formation.

Two Person File Military Formation

An illustration of a two person file military formation.

Illustration of the resultant vector when four vectors are acting upon a body at point P.

Resultant Vector From 4 Forces

Illustration of the resultant vector when four vectors are acting upon a body at point P.