LINKS TO LEARN MORE BELOW! Get my favorite brain food delivered to your door: http://www.curiositybox.com Twitter: http://twitter.com/DoOnlineNowGuys Instagram: http://instagr.am/doonlinenowguys Vsauce PO Box: PO Box 33168 L.A. CA 90033 Wask (strange objects like the short-sided ruler): https://waskstudio.com https://twitter.com/waskstudio Thales's Theorem on wikipedia: https://en.wikipedia.org/wiki/Thales%27s_theorem Thales's Theorem is a special case of the inscribed angle theorem: https://en.wikipedia.org/wiki/Inscribed_angle "axiom" vs "postulate" vs "theorem": https://math.stackexchange.com/questions/7717/difference-between-axioms-theorems-postulates-corollaries-and-hypotheses The axioms of Euclidean plane geometry: http://www.math.brown.edu/~banchoff/Beyond3d/chapter9/section01.html sum of internal angles in a triangle: https://www.cut-the-knot.org/triangle/pythpar/AnglesInTriangle.shtml https://en.wikibooks.org/wiki/Trigonometry/Proof:_Angles_sum_to_180 https://en.wikipedia.org/wiki/Sum_of_angles_of_a_triangle https://complete-concrete-concise.com/mathematics/proving-that-the-angles-in-a-triangle-sum-up-to-180/ parallel theorems: https://mathbitsnotebook.com/Geometry/ParallelPerp/PPverify.html more circle theorems: https://www.mathsisfun.com/geometry/circle-theorems.html angles opposite equal sides in a triangle are equal: https://gradestack.com/CBSE-Class-9th-Complete/Triangles/Angles-Opposite-to-Equal/14901-2953-3986-study-wtw ***CREDITS*** Hosted by Michael Stevens Edited by Hannah Canetti instagram: @hannaynaycanaynay VFX by Eric Langlay (http://youtube.com/ericlanglay) Music by Jake Chudnow and from AudioNetwork (http://youtube.com/jakechudnow) (https://www.audionetwork.com) ***VSAUCE LINKS*** Vsauce1: http://youtube.com/vsauce1 Vsauce2: http://youtube.com/vsauce2 Vsauce3: http://youtube.com/vsauce3