New posts in geometry

Could Euclid have proven that real number multiplication is commutative?

real-analysis geometry euclidean-geometry math-history real-numbers

Systematic solution to my soccer ball puzzle

geometry puzzle symmetry

Why is $\arccos(-\frac 13)$ the optimal angle between bonds in a methane ($\rm CH_4$) molecule?

geometry vectors chemistry

Can the inscribed angle theorem be generalized to solid angles in 3D? And beyond to n-dimensional space?

geometry solid-geometry solid-angle

How to find measurements of angle CBD?

geometry triangles angle

Can two figures (of any kind, bounded by curves or not) have the same area and perimeter, but different shapes?

general-topology geometry

Prove that $BC$, $B_1C_1$, $B_2C_2$ are concurrent.

geometry euclidean-geometry geometric-transformation

Polygon Inequality

geometry inequality polygons

Number of directional orders for $n$ points in $\mathbb{R}^d$?

sequences-and-series combinatorics geometry algebraic-topology order-theory

Square inscribed in a right triangle problem

geometry euclidean-geometry circles locus geometric-transformation

When is a polyhedron uniquely determined by its projections?

geometry convex-geometry polyhedra combinatorial-geometry polytopes

ellipse circumference

geometry conic-sections

Conjecture about a point inside an equilateral triangle divided by integer angles

geometry number-theory trigonometry euclidean-geometry plane-geometry

"Inverse" of the inscribed angle theorem

geometry triangles circles

insphere/circumsphere ratio of a polyhedron the same as its dual polyhedron?

geometry polyhedra platonic-solids

Maps of $\mathbb{R}^3$ commuting with the cross product

geometry analytic-geometry functional-equations cross-product

A natural-looking distance formula

geometry metric-spaces

Dot product in coordinates

geometry linear-algebra

19 points on a hexagon

geometry discrete-geometry

Is there a fibre bundle with fibre homeomorphic to $\mathbb R^k$ which cannot be given the structure of a vector bundle?

geometry differential-geometry vector-bundles fiber-bundles