Euclid

In a given circle to inscribe a triangle equiangular with a given triangle.

In a given circle to fit a straight line equal to a given straight line which is not greater than the diameter of the circle.

To construct a segment of a circle containing an angle equal to a given angle.

In a given circle to inscribe an isosceles triangle having the base angles equal to a given angle.

To construct a pillar gnomon which at a given hour of a given day will show the summer solstice.

The laws of nature are but the mathematical thoughts of God.

Geometry enlightens the intellect and sets one's mind at ease.

The study of geometry is that which gives soul to the body of knowledge.

In the beginning, God created the heavens and the earth, and geometry was the language thereof.

Proofs are the currency of geometry.

Axioms are the foundations upon which all geometry rests.

The short-lived nature of our existence should not prevent us from pursuing eternal truths like those in mathematics.

Mathematics is the door and key to the sciences.

To know what is impenetrable to us really exists, manifesting itself as the highest wisdom and the most radiant beauty which our dull faculties can comprehend only in their most primitive forms - this knowledge, this feeling, is at the center of true religiousness.

The elements of geometry are eternal.

Every proposition in geometry is a truth forever.

The mind is sharpened by the study of figures.

Reasoning from first principles is the essence of mathematical proof.

The beauty of mathematics lies in its certainty.

Geometry draws the soul towards truth.