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 Marion Walter’s Theorem Via Mass Points
 Girls’ Angle Bulletin, Volume 7, Number 5
 Cubes in onepoint perspective
 Girls’ Angle Bulletin, Volume 7, Number 4
 Girls’ Angle Bulletin, Volume 7, Number 3
 Intuiting the Chain Rule
 WIM Video: Pick’s Theorem
 Do you believe this?
 Happy New Year!
 Girls’ Angle Bulletin, Volume 7, Number 2
 2013 AIME 2 Problem 10
 Girls’ Angle Bulletin, Volume 7, Number 1
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Author Archives: girlsangle
Marion Walter’s Theorem Via Mass Points
I recently had the good fortune of learning Marion Walter’s theorem from Marion Walter herself: Marion Walter’s Theorem: In a triangle, draw line segments from each vertex to the trisection points on the opposite side. The six drawn line segments … Continue reading
Girls’ Angle Bulletin, Volume 7, Number 5
The electronic version of the latest issue of the Girls’ Angle Bulletin is now available on our website. A paraboloid of revolution adorns the cover. Anna investigates cross sections of paraboloids in this issue’s Anna’s Math Journal. It sure feels like … Continue reading
Posted in math, Math Education
Tagged Brahmagupta, Cailan Li, chicken mcnugget, cyclic quadrilateral, Frobenius coin problem, Johnny Tang, Kate Jenkins, Marie Vitulli, mass points, maximum subsequence, MIT's Aero/Astro, paraboloidal cross sections, permutations, quadratic reciprocity, Valeria Golosov
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Cubes in onepoint perspective
This post is a reply to Jamie’s comment on Drawn to Math: Would anyone know how to construct a cube in one point perspective? This is an excellent question because it isolates an important, simplified situation that enables one to study key aspects of … Continue reading
Posted in applied math, math
Tagged cubes, geometry, onepoint perspective, perspective drawing, similarity
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Girls’ Angle Bulletin, Volume 7, Number 4
The electronic version of the latest issue of the Girls’ Angle Bulletin is now available on our website. The cover features a planar configuration by Leah Berman, associate professor of mathematics at the University of Alaska Fairbanks. There are 240 … Continue reading
Girls’ Angle Bulletin, Volume 7, Number 3
The electronic version of the latest issue of the Girls’ Angle Bulletin is now available on our website. Much of this issue is about the center of mass, including Julia Zimmerman’s cover drawing which features a mobile fantasy. In Math … Continue reading
Posted in math, Math Education
Tagged center of mass, gravity, Karen Smith, law of the lever, mass points, mobiles, vectors, WallaceBolyaiGerwien theorem, x to the x
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Intuiting the Chain Rule
If you’ve just learned the chain rule but feel that you have no intuition for it, this post might help. Recall that the chain rule tells us how to compute the derivative of a composite function. Specifically, suppose and are … Continue reading
WIM Video: Pick’s Theorem
In our latest WIM Video, Depaul University Associate Professor of Mathematics Bridget Tenner discusses Pick’s theorem. The Girls’ Angle WIM Video series is the brainchild of Girls’ Angle director Elisenda Grigsby. WIM Videos are often shot on the spur of the moment … Continue reading
Posted in math, Math Education, WIM videos
Tagged area, Bridget Tenner, equilateral triangles, lattice polygons, Pick's theorem
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Do you believe this?
Here’s a triangle: I’ll use the vertex labels to also denote the corresponding angle measures. Take the sines of all 3 angles in the triangle: , , and . Would you believe it if I told you that these three … Continue reading
Posted in Contest Math, math
Tagged law of cosines, Ptolemy's theorem, similarity, sine, triangles, trigonometry
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Happy New Year!
How many dots are in the base?
Girls’ Angle Bulletin, Volume 7, Number 2
The electronic version of the latest issue of the Girls’ Angle Bulletin is now available on our website. In Bisection Envelopes, a paper to appear in the journal Involve, Noah FechtorPradines proves many interesting properties of the envelope of the set of … Continue reading