I. WE may hence readily infer, that if the Diameter of any Circle be called a the Circumference may be called ea, (for whatever the proportion is between them, i•• may be expressed by the Letter e) and the Area, according to Consectary 2. Definition 15, will be ¼ eaa.
II. If for the Base of any Cylinder or Cone you put ¼ eaa and the Altitude (b) the Solidity of that Cylinder may be rightly expressed by ¼ eaab, by Consect. 5. Definit. 16, and of the Cone by ½ eaab, by Consect. 4. Definit. 17.