Graphic showing the Cartesian coordinate system used by turtle graphics.

A set of circles inscribed between the center point and the radius of a larger circle.

A set of circles inscribed between an inner and an outer circle.

A set of concentric open and filled heart shapes.

A set of concentric hexagons.

A random polygon.

A set of randomly colored, randomly sized and randomly placed stars.

Randomly placed stick men.

This is an adaptation of an article from an early BYTE magazine about using early personal computers to do graphics.

A snowman.

Increasing sized squares each with a common corner point and a different start angle.

A spiral. Original program by Bernie Pope.

A weird colored squiggle.

Many rows and columns of five-pointed stars.

A large yellow five-pointed star.

Randomly colored lines radiating from the center.

Star burst formed from regularly spaced radial lines of two colors.

A set of rectangles that bounce on the edge of the canvas. Original program by Bernie Pope.

A set of dots whose colors change randomly. This was a prototype for a light sequencer.

A program to generate a series of boxes in a Fibonacci sequence. The length of the side of each box is equal to the sum of the lengths of the two preceding boxes.

Random-sized, random-colored rectangles are generated on a white background. Original program by Bernie Pope.

An animation of a stick figure doing jumping jacks.

A set nested triangles that are randomly colored and changing.

A set of nested triangles with progressive color changes to suggest movement toward the center. The program keeps track of the random colors used and migrates the colors from outer to inner triangles.

An example of telling a story with a set of still frames.

A tessellation using squares.

A tessellation using regular hexagons.

A tessellation using equilateral triangles. This pattern is periodic horizontally, but not vertically.

A tessellation using a pentagonal shape that looks like a baseball home plate.

Common brick laying pattern.

Bricks laid in a herring bone pattern.

Basket weave tessellation.

The small angle of a rhombus is 60° so that six can form around a central point. The rest just line up on this initial center. Form is radially symmetric, but is aperiodic. Not sure of the source.

This was a tessellation found on a wall paper pattern.

A series of arcs and curves to test that they can be created from various start points and extents.

A line drawing of uniform triangles forming a compass rose. (The intermediate 8 points, NNE, etc., are of a different size to fit the pattern.) Small angle of triangle has a 45° angle so that 8 of them fit around the central point.

A line drawing forming a compass rose. (The intermediate 8 points, NNE, etc., are of a different size to fit the pattern.) Small angle of triangle has a 45° angle so that 8 of them fit around the central point.

A colorized drawing of uniform triangles forming a compass rose. Small angle of triangle has a 45° angle so that 8 of them fit around the central point.

A set of overlapping squares drawn using squares. Design inspired by a wooden block artwork seen in a restaurant.

A set of overlapping squares drawn in a rasterized method using only line segments and no turns. (This illustrates the concept that there is more than one way to skin a cat.) Design inspired by a wooden block artwork seen in a restaurant.

A tessellation of 30° isosceles triangles forming six pointed stars. This is drawn as a set of central points surrounded by eminating lines that form the triangles. This design was also found in a restaurant.

The US flag.

This is classic Sol LeWitt. He started wall painting with a similar design. Rather than be confined to the limits of a canvas, he chose to paint the entire wall. The theme of the four line types is carried over into many of his conceptual pieces with many permuations. The four line types (according to LeWitt) are: horizontal, vertical, slanting right, and slanting left.

This is a variant of the four line types, where each line type adds to the line types used in the previous quadrant.

LeWitt uses a playful motif of intersecting concentric circles with bands of bold colors. This drawing is a proof of concept of how to calculate the centers of the various sets of concentric circles.

This puzzle consists of nine wooden blocks. The blocks may slide vertically or horizontally when there is space for them to move. There is one large block that is 2 units by 2 units, one horizontal block that is 2 units wide by 1 unit high, four vertical blocks that are 1 unit wide and 2 units high, and four small blocks that are 1 unit wide and 1 unit high. The objective is to move the large block from the top center position to the bottom center position. This puzzle goes by many different names: L'Ane Rouge (The Red Donkey), Haba's Quo Vadis, The VIP puzzle, Tryne's Hako, Square Root, Hix Brix, Mintman, Klotski, the Chessmen, Skor Mor's Ego Buster, Hua Rong Dao (Huarong Path), Daughter in the Box, Psychoteaze, Intreeg.