Diagram illustrating Pythagoras' Theorem: that for a right angled triangle, the square on the hypotenuse is equal to the sum of the squares on the other two sides. Title page of 'The first six books of the Elements of Euclid: in which coloured diagrams and symbols are used instead of letters for the greater ease of learners' by Oliver Byrne, published in London in 1847. Euclid's (330-275 BC) 'Elements of Geometry' incorporated previous works in mathematics such as those of Pythagoras (569BC -c 475BC), the first pure mathematician, as well as Euclid's own findings. The writings deal with plane geometry; solid geometry, including the five Platonic solids; and the theory of numbers, including a proof that there are an infinite number of primes.
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