Fig. 19.

To find the radius of a circle for striking the side of a flaring vessel having the diameters and depth of side given.

Rule

As the difference between the large and small diameter is to the depth of the side, so is the small diameter to the radius of the circle by which it is struck.

Example

Suppose A B C D to be the desired vessel, with a top diameter of 12 inches, bottom diameter 9 inches, depth of side 8 inches. Then as 12 - 9 = 3 : 8 : : 9 to the radius. 8X9 = 72/3 = 24 inches, answer.