...circle is a plane figure contained by one line, which is called the circumference and is such that all lines drawn from a certain point within the figure to the circumference are equal to one another: 16. And this point is called the center of the circle. It is evident that in the first of these statements,...

...enclosed by one or more boundaries. 12. A. circle is a plane figure contained by one line, which is called the circumference, and is such that all straight...point within the figure to the circumference are equal (Fig. 4). 13. And this point is called the centre of the circle (Fig. 4,0). 14. A diameter of a circle...

...Herculaneum 1061. 220The text transmitted by all manuscripts of the Elements (I, definition 15) is: "A circle is a plane figure contained by one line, called the circumference, such that all straight lines emanating from one point inside the figure and falling upon it — upon...

...r2 + R/ + rl) Slant height (/) = V/.2 + (Rr)2 8. Sphere : A sphere is a solid bounded by one surface and is such that all straight lines drawn from a certain point within the solid to the bounding surface are equal. This certain point is called the centre of the sphere. A line...