Square root of the surface of a sphere × 1.772454 = Circumference.

Square of one of its sides × 6 = Surface of a cube.

Area of the base of a square, round or triangular pyramid, or of a cone, × one-third of its altitude = Solidity.

Area of square × .7854 = Area of largest circle within it.

Area of circle × .625 = Area of largest square within it.

Spheres.—Square of circumference × .3183 = Surface of sphere.

Square of diameter × 3.1416 = Surface of sphere.

Square root of surface × .5642 = Diameter of sphere.

Cube of diameter × .5236 = Solidity of sphere.

Cube of circumference × .0169 = Solidity of sphere.