### Area of Parallelogram

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

### Area of Trapezoid

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

### Area of Trapezoid

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

### Area of Triangle

"The triangle ABC is divided into 2 right triangles I and II. ABC is seen to be equal to 1/2 of the…

### Area of Triangle

"The child sees triangle ACB = triangle ADB, and that I + II = CA - DB; and so he sees that the area…

### Area of Triangle

"Fig. 3 shows triangle I = triangle II, III = IV, and so triangle ABC = 1/2 of rectangle ABDE. The fact…

### Circle With Inscribed and Circumscribed Quadrilaterals

Illustration showing a circle with an inscribed and circumscribed quadrilateral.

### Composite Figure

Illustration of a composite figure made up of rings, rectangles, triangles, etc..

### Circle Inside Concentric Rectangles

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

### Cube

A regular body with six square faces; a rectangular parallelopiped, having all its edges equal.

### 3 Square Inscribed In A Dodecagon

Illustration of 3 squares inscribed in an regular dodecagon. Each vertex of the dodecagon is also a…

### Square Circumscribed About A Dodecagon

Illustration of a square circumscribed about a regular dodecagon. This could also be described as a…

### Square Inscribed In A Dodecagon

Illustration of a square inscribed in an regular dodecagon. This could also be described as a regular…

### Squares Inscribed and Circumscribed About a Regular Dodecagon

Illustration of 2 squares; one inscribed in a regular dodecagon and the other circumscribed about the…

### Drawing Lines 2

Shading of the right and lower sides gives dimension to drawings.

### Similar Figures

2 rectangles that are similar figures

### Flashcard of a Parallelogram

A flashcard featuring an illustration of a Parallelogram

### Flashcard of a Pyramid with a Rectangular Base

A flashcard featuring an illustration of a Pyramid with a Rectangular Base

### Flashcard of a Rectangle

A flashcard featuring an illustration of a Rectangle

### Flashcard of a Rhombus

A flashcard featuring an illustration of a Rhombus

### Flashcard of a Trapezoid

A flashcard featuring an illustration of a Trapezoid

### Forms

Showing different types of forms or shapes: rectangle, right triangle, acute triangle, and obtuse triangle.

### Fraction Chart

This fraction chart can be used for students to find A, B, and C in percentage. It can also be used…

### Rectangle Shaped Steel Magnet

An illustration of a rectangle shaped steel magnet with "consequent poles at a and b." -Century, 1889

### Measures of Form

Labeled shapes showing various measures of form.

### Orthographic Pyramid Projection

An orthographic projection of a pyramid from three dimensional space into two dimensional space

### Area of a Parallelogram

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

### Parallelogram and Rectangle Relationship

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

### Decagonal Prism

Illustration of a decagonal prism with regular decagons for bases and rectangular faces. The hidden…

### Decagonal Prism

Illustration of a right decagonal prism with regular decagons for bases and rectangular faces.

### Decagonal Prism Resting On Its Side

Illustration of a right decagonal prism with regular decagons for bases and rectangular faces. The prism…

### Swimming Pool Shaped Like A Decagonal Prism

Illustration of a swimming pool and water hose that is in the shape of a hollow regular decagonal prism…

### First order prism

"The prism of the first order consists of four rectangular vertical faces, each of which intersects…

### Heptagonal/Septagonal Prism

Illustration of a hollow right heptagonal/septagonal prism with regular heptagons/septagons for bases…

### Heptagonal/Septagonal Prism

Illustration of a regular right heptagonal/septagonal prism with regular heptagons/septagons for bases…

### Heptagonal/Septagonal Prism

Illustration of a right heptagonal/septagonal prism with regular heptagons/septagons for bases and rectangular…

### Heptagonal/Septagonal Prism

Illustration of a right heptagonal/septagonal prism with regular heptagons/septagons for bases and rectangular…

### Hexagonal Prism

Illustration of a right hexagonal prism.

### Hexagonal Prism

Illustration of a right hexagonal prism with hidden edges shown.

### Hexagonal Prism

Illustration of a right hexagonal prism with a height less than the length of the edge of the hexagon.

### Hexagonal Prism

Illustration of a right hexagonal prism with a height greater than the length of the edge of the hexagon.

### Hexagonal Prism

Illustration of a right hexagonal prism with hexagons for bases and square faces.

### Hexagonal Prism

Illustration of a right hexagonal prism with hexagons for bases and square faces. The hidden edges are…

### Hexagonal Prism

Illustration of a right hexagonal prism with hexagons for bases and rectangular faces. The height of…

### Nonagonal Prism

Illustration of a right nonagonal prism with regular nonagons for bases and rectangular faces. The hidden…

### Nonagonal Prism

Illustration of a right nonagonal prism with regular nonagons for bases and rectangular faces. The height…

### Octagonal Prism

Illustration of a right octagonal prism with regular octagons for bases and rectangular faces. The hidden…

### Octagonal Prism

Illustration of a right octagonal prism with regular octagons for bases and rectangular faces. The height…

### Octagonal Prism

Illustration of a right octagonal prism with octagons for bases and rectangular faces. The height of…

### Octagonal Prism Resting On Side

Illustration of a right octagonal prism, with octagons for bases and rectangular faces, that is resting…

### Pentagonal Prism

Illustration of a right pentagonal prism with regular pentagons for bases and rectangular faces. The…

### Pentagonal Prism

Illustration of a right pentagonal prism with regular pentagons for bases and rectangular faces. The…

### Pentagonal Prism

Illustration of a right pentagonal prism with regular pentagons for bases and rectangular faces. The…

### Pentagonal Prism

Illustration of a right pentagonal prism with regular pentagons for bases and rectangular faces. The…

### Rectangular Prism

Prism with rectangular bases and cubes drawn in.

### Star-Shaped Decagonal Prism

Illustration of a non-regular decagonal prism in the shape of a star. Then ends/bases are made of star-shaped…

### Star-Shaped Decagonal Prism

Illustration of a non-regular decagonal prism in the shape of a star. Then ends/bases are made of star-shaped…

### Star-Shaped Decagonal Prism

Side view of a non-regular decagonal prism in the shape of a star. Then ends/bases are made of star-shaped…

### 2 Octagonal Prisms

Illustration of 2 right octagonal prisms with congruent bases, but different heights. The height of…

### 2 Similar Octagonal Prisms

Illustration of 2 Similar right octagonal prisms. The height and length of the edges of the smaller…