In this event organised by Women in Mathematical Sciences at Lund, we have a guest speaker from the University of Wuerzburg. Annika Moucha is a PhD student, and her research interests lie in analysis. The talk will take place in MH:Hörmander in the MH building. Annika will tell us something about her research and about her career path, in a talk accessible for undergraduate students. Everybody is welcome and no registration is necessary. There will also be a get-together with the speaker after the talk. If you are interested in joining us for this get-together, please contact us at: women@math.lu.se

Title: Why the sum of the interior angles of a triangle is not always 180°

Abstract: When we are asked to draw a triangle, probably most of us take a sheet of paper, a pencil and preferably a ruler and draw three points that are connected by three straight lines. Then, we can measure the interior angles and always end up with a sum of 180°. This is exactly what we expect since this is a basic fact — in euclidean geometry. However, the situation becomes different if we are asked to draw a triangle in a specific non-euclidean geometry. In euclidean geometry we deal with a flat space like R^2 — or a sheet of paper — and the distance between two points is measured by the euclidean metric. Then, a straight line is the shortest connection between two points in this space with respect to the euclidean metric. Opposed to this, in non- euclidean geometry both the space and the metric can be different. Two examples of non-euclidean geometries are the spherical and the hyperbolic geometry. In this talk we give an introduction to both of them, explore their differences and similarities with euclidean geometry and, of course, investigate their triangles.