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

### 4 Parallel Lines Cut By 2 Transversals

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

### Face Angles of Convex Polyhedral Angle

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

### Perpendiculars To The Sides Of An Angle

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

### Perpendiculars To The Sides Of An Angle

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

### Equal Right Angles

Illustration used to prove that all right angles are equal.

### Symmetrical or Equal Trihedral Angles

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

### Squaring Binomial (a + b)

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

### Squaring Binomial (a - b)

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

### Circle Diameters

If every diameter is perpendicular to its conjugate, the conic is a circle.

### Angles Inscribed in the Same Segment Circle Proof

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

### Inscribed Angle in a Circle Proof

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

### Inscribed Angle in a Circle Proof

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

### Inscribed Angle in a Circle Proof

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

### Obtuse Angles Inscribed in Circle Proof

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

### Equal Tangents to Circle Theorem

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

### Tangent to Perpendicular Radius Circle Theorem

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

### Diameter Perpendicular to a Chord in a Circle

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

### Equal Chords in Equal Circles Theorem

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

### Equal Chords in Equal Circles Theorem

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

### Unequal Chords in Circles Theorem

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

### Unequal Chords in Equal Circles Theorem

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

### Unequal Chords in Equal Circles Theorem

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

### Circumferences of 2 Circles

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

### Circular Involution

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

### Intersecting Lines Corollary

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

### Perpendicular to Line Corollary

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

### Cross-Ratio Four Points

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

### Second Order Curve Tangents

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

### Dedekind Property 1

Illustration 1 of the Dedekind axiom.

### Dedekind Property 2

Illustration 2 of the Dedekind axiom.

### Dedekind Property 3

Illustration 3 of the Dedekind axiom.

### Dedekind Property 4

Illustration 4 of the Dedekind axiom.

### Plane Bisecting Dihedral Angle

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

### Equilateral Triangle Inscribed In An Equilateral Triangle

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

### Volume of Frustum of a Pyramid

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

### Model Of Geometric Proportions In A Circle

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

### Model Of Geometric Proportions In A Triangle

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

### Model Of Geometric Proportions

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

### Model Of Geometric Proportions

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

### Model Of Geometric Proportions

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

### Model Of Geometric Proportions

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

### Model Of Geometric Proportions

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

### Model Of Geometric Relationships In 2 Circles

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

### Model Of Geometric Relationships In 2 Circles

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

### Model Of Geometric Relationships In A Circle

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

### Model Of Geometric Relationships In A Circle

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

### Involution

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

### Angle Bisectors In An Isosceles Triangle

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

### Base Angles In An Isosceles Triangle

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

### Equal Segments In An Isosceles Triangle

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

### Equal Segments In An Isosceles Triangle

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

### Equal Segments In An Isosceles Triangle

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

### Equal Segments In An Isosceles Triangle

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

### Perpendicular To Line In Plane

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

### Plane Perpendicular To Line

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

### Planes Perpendicular To A Line

"Two planes perpendicular to the same straight line are parallel."

### Parallel Lines

"Two straight lines perpendicular to the same plane are parallel."

### Parallel Lines

"Two straight lines that are parallel to a third are parallel to each other."

### Line Joining Midpoints on a Triangle

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

### 2 Equal Parallelograms

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