This mathematics ClipArt gallery offers 127 images that can be used to demonstrate various geometric theorems and proofs.

Illustration used to prove the theorem "If three or more parallel lines intercept equal segments on…

Diagram used to prove the theorem: "The sum of the face angles of any convex polyhedral angle is less…

Illustration used to show "The two perpendiculars to the sides of an angle from any point in its bisector…

Illustration used to show "The two perpendiculars to the sides of an angle from any point not in its…

Diagram used to prove the theorem: "Two trihedral angles, which have three face angles of the one equal…

An illustration showing how to square binomial (a + b). (a + b)² = a² + 2ab + b².

An illustration showing how to square binomial (a - b). (a - b)² = a² - 2ab + b².

Illustration of a circle used to prove "All angles inscribed in the same segment are equal."

Illustration of a circle with an inscribed angle that can be used to prove that "An inscribed angle…

Illustration of a circle with an inscribed angle that can be used to prove that "An inscribed angle…

Illustration of a circle with an inscribed angle that can be used to prove that "An inscribed angle…

Illustration of a circle used to prove "Any angle inscribed in a segment less than a semicircle is an…

Illustration used to show that "If two tangents are drawn from any given point to a circle, those tangents…

Illustration used to show that "A tangent to a circle is perpendicular to the radius drawn to the point…

Illustration used to show that "The diameter perpendicular to a chord bisects the chord and also its…

Illustration used to show that "In equal circles, or in the same circle, if two chords are equal, they…

Illustration used to show that "In equal circles, or in the same circle, if two chords are equal, they…

Illustration used to show that "In equal circles, or in the same circle, if two chords are unequal,…

Illustration used to show that "In equal circles, or in the same circle, if two chords are unequal,…

Illustration used to show that "In equal circles, or in the same circle, if two chords are unequal,…

Illustration used to prove "If two circumferences meet at a point which is not on their line of centers,…

Every elliptical involution has the property that there are two definite points in the plane from which…

Illustration used to prove the corollary that "Two lines perpendicular respectively to two intersecting…

Illustration used to prove the corollary that "From a point outside a line there exists only one perpendicular…

The cross-ratio of four points in a line is equal to the cross-ratio of their projections on any other…

Any four-point on a curve of the second order and the four-side formed by the tangents at these points…

Diagram used to prove the theorem: "Every point in a plane which bisects a dihedral angle is equidistant…

Illustration used to prove that triangle EFD is equilateral given that triangle ABC is equilateral and…

Diagram used to prove the theorem: "The volume of the frustum of a pyramid (cone) is equal to the sum…

An illustration showing a model of a circle with intersecting chords that illustrates the following…

An illustration showing a model of a triangle that illustrates the following relationship: a:c = d:(b…

An illustration showing a quadrilateral model that illustrates the following relationships: a:b = c:d,…

An illustration showing a model that illustrates the following relationships: a:b = c:d, ad = bc. Product…

An illustration showing a model that illustrates the following relationships: a:b = c:b, ab = c²,…

An illustration showing a model that illustrates the following relationship: A:B = a:b.

An illustration showing a model that illustrates the following relationships: a:x = x:a - x, x = √(a²…

An illustration showing a model of 2 circles with tangent lines, diameters, and radii that illustrates…

An illustration showing a model of 2 circles with tangent lines, diameters, and radii that illustrates…

An illustration showing a model of a circle with an exterior angle formed between a tangent and a secant…

An illustration showing a model of a circle with angles formed between tangents and secants that illustrates…

The three points in which any line cuts the sides of a triangle and the projections, from any point…

Illustration showing that if two angles of a triangle are equal, the bisectors of these angles are equal.

Illustration showing that can be used to prove that the base angles of an isosceles triangle are equal.

Illustration showing that if equal segments measured from the vertex are laid off on the arms of an…

Illustration showing that if equal segments prolonged through the vertex are laid off on the arms of…

Illustration showing that if equal segments measured from the end of the base are laid off on the base…

Illustration showing that if equal segments measured from the end of the base prolonged are laid off…

"If from the foot of a perpendicular to a plane a straight line is drawn at right angles to any line…

"All the perpendiculars to a straight line at the same point lie in a plane perpendicular to the line."

Illustration used to prove "The line joining the mid-points of two sides of a triangle is parallel to…

Illustration used to prove the theorem "Two parallelograms are equal if two sides and the included angle…