Euclidean geometry equal (SAS), or two angles and a side equal (ASA) (Book I, propositions 4, 8, and 26). Triangles with three equal angles (AAA) are similar, but not necessarily congruent. Also, triangles with two equal sides and an adjacent angle are not necessarily equal or congruent. The sum of the angles of a triangle is equal to a straight angle (180 degrees). This causes an equilateral triangle to have three interior angles of 60 degrees. Also, it causes every triangle to have at least two acute angles and up to one obtuse or right angle. The celebrated Pythagorean theorem (book I,
Triangle and Robert which Triangle and Robert currently live. This ontological dispute was eventually abandoned when Triangle and Robert were called away on another wacky adventure. "Triangle and Robert" won Best Minimalist Comic in the 2001 Web Cartoonist's Choice Awards. Triangle and Robert Triangle and Robert is a webcomic by Patrick Shaughnessy that ran from August 1999 to September 2007. It is about the adventures of two polygons, an equilateral triangle named 'Triangle', and a rhombus named 'Robert'. As Patrick Shaughnessy, appearing in the strip as 'the Cartoonist', has explained on many occasions, he can't draw, and he makes up the story as