Multiple choice general knowledge math & puzzles

According to him, sum of the angles of a triangle is greater than 180 degree...

  1. Euclid

  2. Riemann

  3. Lobachevsky

  4. It is impossible!
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In non-Euclidean geometries, the sum of angles in a triangle differs from 180 degrees. In Riemannian geometry (spherical/elliptic geometry), the angle sum is always greater than 180 degrees - think of a triangle drawn on a sphere where the sides are great circle arcs. Lobachevsky developed hyperbolic geometry where the sum is less than 180 degrees.

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