A

David

Darling

GEOMETRY

  • acute
  • affine geometry
  • alternate
  • altitude
  • angle
  • annulus
  • apex
  • apothem
  • Apollonius problem
  • arc
  • area
  • asymptote
  • Aubel's theorem
  • axis
  • axis of symmetry

  • Bang's theorem
  • bisecting an angle
  • Blanche's dissection
  • Brianchon's theorem
  • butterfly theorem

  • cannonball problem
  • cathetus
  • central angle
  • centroid
  • chord
  • circumcenter
  • circumference
  • circumscription
  • compasses
  • complementary angles
  • congruent
  • constructible
  • coplanar
  • correspondence
  • cosine rule
  • curvature
  • curvature tensor
  • curve

  • de Malve's theorem
  • Descarte's circle theorem
  • descriptive geometry
  • diagonal
  • diameter
  • differential geometry
  • dihedral angle
  • dimension
  • dissection
  • duplicating the cube

  • elliptical geometry
  • Euclidean geometry
  • Euclidean space
  • Euclid's postulates
  • exterior angle

  • Fagnano's problem
  • Flatland
  • focal radius
  • focus
  • fourth dimension

  • geodesic
  • geometry
  • great circle

  • Hadwiger problem
  • harmonic points
  • Hero's formula
  • higher dimensions
  • hole-through-a-sphere problem
  • hyperbolic geometry
  • hypercube
  • hypersphere
  • hypotenuse

  • incenter
  • inscribed angle
  • inscription
  • isogonal conjugate
  • isometry
  • isoperimetric inequality
  • isosceles
  • isotomic conjugate
  • isovolume problem

  • Johnson's theorem

  • Kakeya needle problem
  • Kakeya needle problem

  • Langley's adventitious angles
  • latus rectum
  • length
  • line
  • loculus of Archimedes
  • locus

  • map
  • Mascheroni construction
  • metric
  • mensuration
  • Morley's miracle
  • moving sofa problem

  • Nagel point
  • Neusis construction
  • nine-point circle
  • non-Euclidean geometry

  • oblique
  • opposite angles
  • orthogonal

  • packing
  • parallel postulate
  • Pascal's mystic hexagon
  • perimeter
  • perpendicular
  • perspective
  • Pick's theorem
  • plane
  • point
  • polytope
  • Poncelet's theorem
  • Prince Rupert's problem
  • projection
  • projective geometry
  • prolate
  • Pythagoras's theorem

  • quadrature

  • radial symmetry
  • radius
  • reflection
  • Riemannian geometry
  • rope-around-the-Earth puzzle
  • rotation
  • ruler-and-compass construction

  • salient
  • secant
  • set square
  • similar
  • six circles theorem
  • Soddy's formula
  • Sperner's lemma
  • spherical coordinates
  • spherometer
  • squaring the circle
  • squaring the square
  • Steiner-Lehmus theorem
  • straight
  • supplementary angles
  • Sylvester's problem of collinear points
  • symmedian

  • tangent
  • transformation
  • translation
  • transversal
  • trigonometric function
  • trigonometry
  • trihedron
  • trisecting an angle
  • trisector theorem
  • two-dimensional worlds

  • unilluminable room problem

  • vertex
  • Viviani's theorem
  • volume