• Thumbnail for Intersecting chords theorem
    In Euclidean geometry, the intersecting chords theorem, or just the chord theorem, is a statement that describes a relation of the four line segments created...
    4 KB (529 words) - 17:37, 27 March 2025
  • Thumbnail for Power of a point
    Point Theorem at cut-the-knot Pythagorean Theorem (Proof #22) at cut-the-knot Intersecting Chords Theorem at cut-the-knot Intersecting Chords Theorem With...
    19 KB (3,476 words) - 09:59, 23 June 2025
  • Thumbnail for Intersecting secants theorem
    geometry, the intersecting secants theorem or just secant theorem describes the relation of line segments created by two intersecting secants and the...
    2 KB (255 words) - 16:24, 30 August 2023
  • Thumbnail for Butterfly theorem
    other chords AB and CD are drawn; AD and BC intersect chord PQ at X and Y correspondingly. Then M is the midpoint of XY. A formal proof of the theorem is...
    4 KB (659 words) - 09:23, 27 February 2025
  • Thumbnail for Tangent–secant theorem
    tangent-secant theorem can be proven using similar triangles (see graphic). Like the intersecting chords theorem and the intersecting secants theorem, the tangent-secant...
    2 KB (212 words) - 07:43, 4 February 2025
  • Thumbnail for Geometric mean theorem
    triangle. The theorem can also be thought of as a special case of the intersecting chords theorem for a circle, since the converse of Thales' theorem ensures...
    9 KB (1,183 words) - 22:17, 19 April 2025
  • Thumbnail for Circular arc
    of the diameter, with length 2r − H. Applying the intersecting chords theorem to these two chords produces H ( 2 r − H ) = ( W 2 ) 2 , {\displaystyle...
    6 KB (926 words) - 23:14, 1 April 2024
  • Thumbnail for Ptolemy's theorem
    CD}}\end{aligned}}} Casey's theorem Intersecting chords theorem Greek mathematics C. Ptolemy, Almagest, Book 1, Chapter 10. Wilson, Jim. "Ptolemy's Theorem." link verified...
    28 KB (5,051 words) - 22:17, 19 April 2025
  • Thumbnail for Inscribed angle
    inscribed angle is the angle formed in the interior of a circle when two chords intersect on the circle. It can also be defined as the angle subtended at a point...
    12 KB (1,346 words) - 21:42, 24 February 2025
  • Thumbnail for Parabola
    Parabola (redirect from Lambert's Theorem)
    {\mathrm {CM} }}=2r}  (PMCK is a parallelogram). Using the intersecting chords theorem on the chords BC and DE, we get B M ¯ ⋅ C M ¯ = D M ¯ ⋅ E M ¯ . {\displaystyle...
    80 KB (13,447 words) - 05:14, 4 July 2025
  • Thumbnail for Apollonius's theorem
    In geometry, Apollonius's theorem is a theorem relating the length of a median of a triangle to the lengths of its sides. It states that the sum of the...
    7 KB (776 words) - 09:17, 27 March 2025
  • Thumbnail for Cyclic quadrilateral
    known as the intersecting chords theorem since the diagonals of the cyclic quadrilateral are chords of the circumcircle. Ptolemy's theorem expresses the...
    31 KB (4,099 words) - 14:05, 6 July 2025
  • angle theorem (geometry) Intercept theorem (Euclidean geometry) Intersecting chords theorem (Euclidean geometry) Intersecting secants theorem (Euclidean...
    78 KB (6,296 words) - 20:31, 6 July 2025
  • Thumbnail for Euclid
    the later tradition of Alexandria. In the Elements, Euclid deduced the theorems from a small set of axioms. He also wrote works on perspective, conic sections...
    45 KB (4,421 words) - 18:20, 2 June 2025
  • Thumbnail for A History of Greek Mathematics
    theorem Intersecting chords theorem Intersecting secants theorem Law of cosines Pons asinorum Pythagorean theorem Tangent-secant theorem Thales's theorem Theorem...
    14 KB (1,558 words) - 22:49, 22 May 2025
  • Thumbnail for Ultraparallel theorem
    Beltrami-Klein model are two non-intersecting chords. But they actually intersect outside the circle. The polar of the intersecting point is the desired common...
    6 KB (991 words) - 03:38, 29 September 2024
  • Thumbnail for Chord (geometry)
    the circular arc on the boundary. Scale of chords Ptolemy's table of chords Holditch's theorem, for a chord rotating in a convex closed curve Circle graph...
    6 KB (740 words) - 00:27, 8 May 2025
  • Thumbnail for Squaring the circle
    proven to be impossible, as a consequence of the Lindemann–Weierstrass theorem, which proves that pi ( π {\displaystyle \pi } ) is a transcendental number...
    45 KB (4,923 words) - 18:18, 19 June 2025
  • Thumbnail for Perpendicular
    any two perpendicular chords intersecting at a given point is the same as that of any other two perpendicular chords intersecting at the same point, and...
    15 KB (2,314 words) - 18:12, 19 May 2025
  • Thumbnail for Constant chord theorem
    The constant chord theorem is a statement in elementary geometry about a property of certain chords in two intersecting circles. The circles k 1 {\displaystyle...
    3 KB (530 words) - 16:23, 15 September 2024
  • Thumbnail for Midpoint theorem (conics)
    geometry, the midpoint theorem describes a property of parallel chords in a conic. It states that the midpoints of parallel chords in a conic are located...
    2 KB (198 words) - 03:07, 5 March 2025
  • Thumbnail for Circle
    Circle (redirect from Secant-secant theorem)
    at A and if AQ is a chord of the circle, then ∠DAQ = ⁠1/2⁠arc(AQ). The chord theorem states that if two chords, CD and EB, intersect at A, then AC × AD...
    46 KB (6,352 words) - 22:13, 11 July 2025
  • lines instead of chords can help to unify statements. As an example of this consider the result: If two secant lines contain chords AB and CD in a circle...
    8 KB (1,006 words) - 06:27, 12 March 2025
  • Thumbnail for Ancient Greek mathematics
    Greek mathematics is obscure, and traditional narratives of mathematical theorems found before the fifth century BC are regarded as later inventions. It...
    56 KB (6,581 words) - 22:16, 11 July 2025
  • Thumbnail for Dividing a circle into areas
    Every chord that is cut by another (i.e., chords not in group 1) must contain two group 3 edges, its beginning and ending chordal segments. As chords are...
    13 KB (1,956 words) - 09:44, 31 January 2025
  • astronomy as modeled by the celestial sphere. Primarily consisting of theorems which were known at least informally a couple centuries earlier, the Spherics...
    16 KB (1,486 words) - 23:00, 5 February 2025
  • Thumbnail for Eyeball theorem
    examination paper. A variant of this theorem states that if one draws line F J {\displaystyle FJ} in such a way that it intersects c P {\displaystyle c_{P}} for...
    3 KB (388 words) - 03:10, 3 May 2025
  • theorem Intersecting chords theorem Intersecting secants theorem Law of cosines Pons asinorum Pythagorean theorem Tangent-secant theorem Thales's theorem Theorem...
    2 KB (210 words) - 16:37, 29 April 2025
  • Thumbnail for Descartes' theorem
    In geometry, Descartes' theorem states that for every four kissing, or mutually tangent circles, the radii of the circles satisfy a certain quadratic...
    51 KB (6,411 words) - 13:40, 13 June 2025
  • Thumbnail for History of trigonometry
    angles, respectively. Theorems on the lengths of chords are applications of the law of sines. And Archimedes' theorem on broken chords is equivalent to formulas...
    53 KB (6,835 words) - 05:32, 11 June 2025