Page:An introduction to linear drawing.djvu/97

 78

154,6

75,3

4638 7730

10822

11641,38

That is, 11641 square inches, and 38 hundredths of a square inch.

3.	A yard of a rectangular form, is 2023 inches long, and 1145 wide, what is its aréa or surface ì

4.	A house is 388 inches long, and 146 wide, how many square inches of ground does it cover?

Problem II. The èutface of an upright prism with- out including the two bases, is found by multiplying the iieight by the circumference of the base.

All the làtéràl faces or sides of the body are reCtàn- giés, and còme under the preceding rule.

Example 1. A man wishes to plaster the walls of the room mentioned in No. '1 of the last problem. These walls are 64,6 inches high, how many superficial inches do they contain? The room forms a parallelo- piped, 2023 inches long, 1145 wide, and 84,6 high. Double the width and length, and add them together, and you have the whole length of the walls, 6336 inches. Multiply this by the height, and you have the answer in square inches.

1145 1145 20£3 2023

6336 84,6

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3S016 25344 bÓÒ88

536025,6 Ans.