Elementary Geometry

Author:
Ryan Hirst

Theorems from plane geometry. Euclid's Elements are here: http://www.geogebratube.org/collection/show/id/2554

  • Triangle Inscribed in a Circle

    Triangle Inscribed in a Circle

  • Inscribe a circle in a triangle.

    Inscribe a circle in a triangle.

  • Circle Through Three Points

    Circle Through Three Points

  • Medians and the Centroid

    Medians and the Centroid

  • Divide a circle into three equal sectors.

    Divide a circle into three equal sectors.

  • A quadrilateral inscribed in a circle

    A quadrilateral inscribed in a circle

  • The Diagonals of Trapezoid

    The Diagonals of Trapezoid

  • Tangents from point to circle

    Tangents from point to circle

  • The altitude of a right angle (and its children)

    The altitude of a right angle (and its children)

  • Draw the sine squared of an angle

    Draw the sine squared of an angle

  • The Secant Theorem

    The Secant Theorem

  • Pappus' Theorem

    Pappus' Theorem

  • Pole and Polar 1

    Pole and Polar 1

  • Inscribe a chord in a given arc of a circle

    Inscribe a chord in a given arc of a circle

  • Heron's Formula, Geometric Proof

    Heron's Formula, Geometric Proof

  • The Locus of Points Equidistant from Two Circles

    The Locus of Points Equidistant from Two Circles

  • Archimedes' Formula for π (pi)

    Archimedes' Formula for π (pi)

  • Angle Bisector, ratio of sides

    Angle Bisector, ratio of sides

  • Draw Length Squared

    Draw Length Squared

  • Similarity points

    Similarity points

  • Centroid of a polygon

    Centroid of a polygon

  • Centroid of a triangle

    Centroid of a triangle

  • I am a rhombus

    I am a rhombus

  • Rhombus & Circle, 2

    Rhombus & Circle, 2

Next
Triangle Inscribed in a Circle

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