## Keynote Presentations

#### Event Title

In the Shadow of Desargues

#### Location

Saint John's University

#### Event Website

http://www.csbsju.edu/Mathematics/Pi-Conference.htm

#### Start Date

13-4-2013 12:00 PM

#### End Date

13-4-2013 1:00 PM

#### Description

Those of us who teach projective geometry often nod to perspective art as the spark from which projective geometry caught fire and grew. This talk looks directly at projective geometry as a tool to illuminate the workings of perspective artists. We will particularly shine the light on at Desargues' triangle theorem (which says that any pair of triangles that is perspective from a point is perspective from a line), together with an even simpler theorem (you have to see it to believe it!). Given any convoluted, complicated polygonal object, these theorems allow us to draw that object together with something that is related to it--- its shadow, reflection, or other rigid symmetries---and we'll show how this works. (If you enjoy doodling or sketching, bring your pencil, a good eraser, and a straightedge.)

#### Share

COinS

Apr 13th, 12:00 PM Apr 13th, 1:00 PM

In the Shadow of Desargues

Saint John's University

Those of us who teach projective geometry often nod to perspective art as the spark from which projective geometry caught fire and grew. This talk looks directly at projective geometry as a tool to illuminate the workings of perspective artists. We will particularly shine the light on at Desargues' triangle theorem (which says that any pair of triangles that is perspective from a point is perspective from a line), together with an even simpler theorem (you have to see it to believe it!). Given any convoluted, complicated polygonal object, these theorems allow us to draw that object together with something that is related to it--- its shadow, reflection, or other rigid symmetries---and we'll show how this works. (If you enjoy doodling or sketching, bring your pencil, a good eraser, and a straightedge.)

http://digitalcommons.csbsju.edu/math_pi_mu_epsilon/2013/Keynote/2