# Commit 2023-03-16 11:15 eea141bc

View on Github →refactor(geometry/euclidean): split out spheres (#18220) Rearrange material related to spheres as follows:

`geometry.euclidean.sphere.power`

has most of the content from the previous`geometry.euclidean.sphere`

(intersecting chords / secants, which at some point should probably be refactored using an explicit definition of the power of a point).`geometry.euclidean.sphere.ptolemy`

has the proof of Ptolemy's theorem that was previously in`geometry.euclidean.sphere`

.`geometry.euclidean.sphere.basic`

has most of the material previously in`geometry.euclidean.basic`

: definitions of`sphere`

,`cospherical`

and`concyclic`

and associated lemmas.`geometry.euclidean.sphere.second_inter`

has the definition and lemmas about`second_inter`

. There are no changes to API or proofs.