83, 89, 97..............the last 3 primes in 2 digits......2 and 3 again......2 begin with a 8.........1828......in e......twice..........83 + 97 = 180........the number of degrees in any 2 d triangle...........a triangle has 3 sides..........yet another...2, 3.......pattern.............a straight line also has 180 degrees......in the unit circle.....180 degrees is pi.........89 + 97 = 186..........like the speed of light..

Area of triangles (article) | Khan Academy

https://www.khanacademy.org/math/basic-geo/...area.../area-triangle/a/area-of-triangle

Intuition for why the area of a triangle is one half of base times height.