op art | RobertLovesPi.net

A Rotating Great Rhombicosidodecahedron, with Spinning Mandalas On Its Faces

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A Rotating Great Rhombicosidodecahedron, with Spinning Mandalas On Its Faces

This polyhedron is also known as the truncated icosidodecahedron. However, I prefer the name which appears in the title of this post.

I made the image which appears on each face with Geometer’s Sketchpad and MS-Paint, and then used Stella 4d to project this image onto each face of this polyhedron, and create this rotating .gif image.

If you’d like to try Stella 4d for free, just visit this site: http://www.software3d.com/Stella.php. To my knowledge, a free trial download is only available for Stella 4d, but not for the other programs mentioned above.

Only Nine School Days Left This Year

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Only Nine School Days Left This Year

Due to an unusual amount of Winter weather this school year, the school year where I teach has been extended to June 6, creating what many are calling “the school year that will not end.” It will end, of course, but the already-long wait for Summer vacation is getting to many of us — students, parents, teachers, and administrators alike.

The countdown is now at nine school days left: four next week, and five the week after that. In honor of this point in the countdown, I created this image based on the number nine, using Geometer’s Sketchpad and MS-Paint.

Cuboctahedron with Mandalas

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Cuboctahedron with Mandalas

The images on the faces of this polyhedron may be seen in still black and white in the previous post. I used Geometer’s Sketchpad and MS-Paint to make the flat image, and then Stella 4d to put it all together. You may try Stella for free at http://www.software3d.com/Stella.php.

A Snowflake Made of Circles

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A Snowflake Made of Circles

Fifteen

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Fifteen

A Collection of Nine-Point Circles

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A Collection of Nine-Point Circles

[Note: if you are not familiar with the nine-point circle already, you may wish to see the next post on this blog, where it is explained in detail.]

The largest circle shown here is the circumscribed circle for a large equilateral triangle, and its nine-point circle is shown as well. Also, each altitude of an equilateral triangle splits it into two 30-60-90 triangles. Since there are three such altitudes, there are six 30-60-90 triangles of this size — and all their nine-point circles are shown as well. These three altitudes, taken together, also split the equilateral triangle into six smaller 30-60-90 triangles, and their nine-point circles are also shown here.