Euclid

Mathematics Greek -325 – -265 439 quotes

Father of geometry, wrote Elements

Quotes by Euclid

The volume of a cone is one-third the volume of a cylinder with the same base and height.

Elements (Book XII, Proposition 10) -300

The volume of a pyramid is one-third the volume of a prism with the same base and height.

Elements (Book XII, Proposition 5) -300

Spheres are to one another in the triplicate ratio of their diameters.

Elements (Book XII, Proposition 18) -300

The elements of a cone are similar to the elements of a pyramid.

Elements (Book XII, Proposition 11) -300

In any right-angled triangle, the square on the side subtending the right angle is equal to the squares on the sides containing the right angle.

Elements (Book I, Proposition 47 - Pythagorean theorem) -300

Magnitudes are said to be in the ratio which like magnitudes, when one is taken as the first and the other as the second, have when compared in order.

Elements (Book V, Definition 3) -300

Ratios which are the same with the same ratio are the same with one another.

Elements (Book V, Proposition 11) -300

If there be any number of magnitudes whatever which are in proportion, they will also be in proportion alternately.

Elements (Book V, Proposition 16) -300

Equal triangles upon equal bases in the same parallels are equal.

Elements (Book VI, Proposition 1) -300

Triangles upon equal bases and in the same parallels are equal.

Elements (Book VI, Proposition 2) -300

If four straight lines be proportional, the rectangle contained by the first and fourth is equal to the rectangle contained by the second and third.

Elements (Book VI, Proposition 17) -300

In equal circles equal angles stand on equal arcs, whether they stand at the centres or at the circumferences.

Elements (Book III, Proposition 26) -300

The angle subtended by an arc at the centre is double that subtended at the circumference.

Elements (Book III, Proposition 20) -300

The opposite sides and angles of a parallelogram are equal.

Elements (Book I, Proposition 34) -300

The diagonals of a parallelogram bisect each other.

Elements (Book I, Proposition 41) -300

The square on the hypotenuse is equal to the sum of the squares on the other two sides.

Elements (Book I, Proposition 47) -300

A solid angle is the inclination of more than two plane angles to one another, which are contained by straight lines lying in one plane and meeting one another at one point.

Elements (Book XI, Definition 12) -300

If two triangles have two angles equal and the sides adjacent to the equal angles equal, then they are congruent.

Elements (Book I, Proposition 26) -300

The area of a circle is equal to the area of a right-angled triangle whose legs are equal to the radius and the circumference of the circle.

Elements (Book XII, Proposition 2) -300

The volume of a sphere is four-thirds times the volume of a cone with the same base and height.

Elements (Book XII, Proposition 18) -300