To Find The Convex Surface Of A Sphere Or Globe

Fig. 12

Rule - Multiply the diameter of the Sphere by its circumference, and the product is its surface; or,

Multiply the square of the diameter by 3.14-16, the product is its surface.

What is the Convex Surface of a globe, 6 1/2 ft., in diameter?

6.5 X 3.1416 X 6.5 = 132.73 square feet; or, 6.52 = 42.25 X 3.1416 = 132.73 square feet the Convex surface.

Fig. 12.

Mensuration Of Solids And Capacities Of Bodies

To Find The Solidity Or Capacity Of Any Figure In The Cubical Form

Rule. - Multiply the length of any one side by its breadth and by the depth or distance to its opposite side, the product is the solidity or capacity in equal terms of measurement.

Example. - The side of a cube is 20 inches, what is the solidity ? 20 X 20 X 20 = 8000 cubic inches; or, 4.6296 cubic feet nearly.

A Rectangular tank is in length 6 feet, in breadth 4 1/2 feet, and in depth 3 feet, required its capacity in cubic feet; also its capacity in U. S. Staudard gallons.

6 X 4.5 X 3 = 81 cubic feet, 81 X 1728 = 139968 ÷ 231 =605.92 gallons.