| Nels Johann Lennes, Frances Jenkins - Arithmetic - 1920 - 360 pages
...area of the circle. In geometry, very much more accurate methods than this are used. The result is : **The surface of a sphere is four times the area of a** circle of the same radius. Since the area of a circle is irr2, it follows that the surface of a sphere... | |
| William Henry Snyder - Science - 1925 - 648 pages
...of a circle is the product of 3.1416 (very nearly *,«•) and the square of the radius (A = irr)2; **the surface of a sphere is four times the area of a** circle through its center (A = 4 irr»). SQUARE CENTIMETER AND SQUARE INCH 1 2 3 4 9 e 7 8 • I "1... | |
| |