Similar to ルーローの三角形

Yff center of congruence

Van Lamoen circle

Erdős–Mordell inequality

Euler line

Carnot's theorem (conics)

Kiepert conics

Conway circle theorem

Conway triangle notation

Schiffler point

Steiner ellipse

Spieker circle

Soddy circles of a triangle

Soddy line

Thales's theorem

Cevian

1 + 1 + 1 + 1 + ⋯

1/2 + 1/4 + 1/8 + 1/16 + ⋯

1/2 − 1/4 + 1/8 − 1/16 + ⋯

1/4 + 1/16 + 1/64 + 1/256 + ⋯

Hundredth

Catalogue of Triangle Cubics

Circumgon

Encyclopedia of Triangle Centers

Circles of Apollonius