直線
まっすぐな線。
厳密な定義だとよくわからん。
line ; linear line
曲線（curve）
放物線、パラボラ（parabola）
平面（plane）
超平面 -- —直線や平面は超平面に含まれる
一次関数（linear function）
極座標（Polar coordinates）
Affine function
Distance from a point to a line
Five points determine a conic, just as two points determine a line
Glossary of Riemannian and metric geometry#R for its meaning in Riemannian geometry.
Incidence (geometry)
Line drawing algorithm
Line segment
Minimal line representation
Number line
Plane (geometry), including Plane (geometry)#Distance from a point to a plane, which generalizes the distance from a point to a line.
Plücker coordinates
Real line
Ridge detection and Hough transform for algorithms for detecting lines in digital images