which is either from a Line to a plain Superficies, or from a plain Superficies to a Solid Body: every of which are considered according to the quantity or form.
The quantity of a Line is length, without breadth or thicknesse, the forme either right or curved.
The quantity of a Superficies consisteth in length and breadth, without thicknesse, the form is divers, either regular or irregular; Regular are Triangles, Squares, Cir∣cles, Pentagons, Hexagons, &c.
An equilaterall Triangle consisteth of three right lines & as many angles, his inscribed side in a Circle contains 120 degrees.
A Square of four equall right lines, and as many right angles, and his inscribed side is 90 degrees.
A Pentagon consisteth of five equall lines and angles, and his inscribed side is 72 degrees of a Circle.
A Hexagon is of six equall lines and angles, and his side within a Circle is 60 degrees, which is equall to the Radius or Semidiameter.
An Angle is the meeting of two lines not in a streight concurring, but which being extended will crosse each o∣ther; but if they will never crosse, then they are parallel.
The quantity of an angle is the measure of the part of a Circle divided into 360 degrees between the open ends, and the angle it self is the Center of the Circle.
The quantity of a Solid consists of length, breadth, and thickness, the form is various, regular or irregular: The five regular or Platonick Bodies are, the Tetrahedron, Hexahedron, Octohedron, Dodecahedron, Icosahedron.
Tetrahedron is a Solid Body consisting of four equall equilaterall Triangles.