" a triangle is a three-sided rectilineal figure."
A triangle is a rectilineal figure; i.e.
Quadrilaterals, hexagons, &c., all of which are rectilineal figures, a triangle is "differentiated" as having three sides.
Since the area of a circle equals that of the rectilineal triangle whose base has the same length as the circumference and whose altitude equals the radius (Archimedes, KIKXou A ir, prop.i), it follows that, if a straight line could be drawn equal in length to the circumference, the required square could be found by an ordinary Euclidean construction; also, it is evident that, conversely, if a square equal in area to the circle could be obtained it would be possible to draw a straight line equal to the circumference.
Wood potentially a table; primary, as an indeterminate something which is a substratum capable of becoming natural substances, of which it is always one; and it is primarily the matter of earth, water, air, fire, the four simple bodies (airxa 6w,uara) with natural rectilineal motions in the terrestrial world (De Gen.
Aristotle could not know enough, physically, about Nature to understand its matter, or its motions, or its forces; and consequently he fell into the error of supposing a primary matter with four contrary primary qualities, hot and cold, dry and moist, forming by their combinations four simple bodies, earth, water, air and fire, with natural rectilineal motions to or from the centre of the earth; to which he added a quintessence of ether composing the stars, with a natural circular motion round the earth.