Εικόνες σελίδας
PDF
Ηλεκτρ. έκδοση

38. At 65 cents a bushel, what should be the price of corn a hektoliter?

39. What is the value of an eighth of a plantation of 600.58 hektares at $25 an acre?

40. The distance by railroad between Boston and New Orleans is 1607 miles. What is it in kilometers?

41. The dome of the capitol at Washington is 287 ft. 6 in high, surmounted by a statue of Liberty 19 ft. 6 in. high. What is the whole height in meters?

42. Bought a roll of carpeting of 65 yards at $ 1.20 a meter, and sold it at the same price a yard. How much did I make by the transaction?

43. The capacity of a certain bin is 40.64 cubic meters. What is the value of the grain that can be put in it at 80 cents a bushel?

QUESTIONS.

197. What is the metric system? 198. What is a meter? 199. An are 200. A stere? 201. A liter? 202. A gram?

203. How are the names of the divisions of the metric units formed? 205. Recite the table of metric measures of length. For what is the meter used? The kilometer?

206. How is a metric number written? 207. How are metric numbers read?

208. Recite the table of metric measures of surface. How is the square meter used? The square kilometer? The are and hektare? 209. Name the measures of volume. How is the cubic meter used? When does it take the name of the stere?

210. Recite the table of measures of capacity. How is the liter used? The hektoliter?

211. Recite the table of measures of weight. For what is the gram used? The kilogram? The metric ton?

212. How many units of one denomination make a unit of another in the metric system? How may a metric number be changed from one denomination to another? When any denomination is taken as the unit, how may the number at the right of the point be read?

MEASUREMENTS.

SURFACES.

214 1. How many square inches in a surface 8 inches long and 1 inch wide? In a surface 8 inches long and 2 inches wide?

2. A path 12 feet long and 2 feet wide has how many square

feet of surface in it?

3. A table is 6 feet long and 4 feet wide. How many square feet of surface has it?

215. A Plane Figure is a portion of a plane surface (Art. 163) bounded by lines.

216. The Perimeter of a plane figure is the sum of its bounding lines.

217. The Area of a plane figure is the surface included within its perimeter.

218. The Dimensions of a rectangle

are its length and breadth.

A rectangle 3 inches long and 2 inches broad contains in one row 3

squares of 1 square inch each; and 2 such rows contain 2 times 3 square inches, or 6 square inches. That is,

The area of a rectangle is equal to the product of its length and breadth, taken in the same denomination.

[graphic]

Also,

One of the dimensions of a rectangle is equal to the area divided by the other dimension.

A

D

219. A Triangle is a plane figure bounded by three straight lines.

The Base of a triangle is the line upon which it stands; and the Altitude is its height above the base, or B the base extended. Thus,

A B is the base, and C D the altitude, of the triangle ABC.

[graphic][subsumed][subsumed][merged small][merged small][merged small]

of the same base and altitude. That is,

The area of a triangle is half the area of a rectangle of the same base and altitude.

221. A Circle may be regarded as consisting of a great number of triangles, whose bases form the circumference of a circle, and whose altitude is the radius of the circle. Hence,

[graphic]

The area of a circle is equal to half the product of the circumference by the radius.

222. The quotient of the circumference of a circle divided by the diameter, to the nearest ten-thousandth, is 3.1416. Hence,

The circumference is equal to the diameter multiplied by 3.1416; the diameter is equal to the circumference divided by 3.1416.

WRITTEN EXERCISES.

4. What is the area of a floor which is 52 feet 9 inches long

[blocks in formation]

5. The area of a floor is 1371 square feet 72 square inches, and its width is 26 feet. What is its length?

[blocks in formation]

6. The base of a triangle is 46 ft. 3 in., and the altitude 35 ft. 6 in. What is its area?

7. The circumference of a circle is 314.16 feet, and its radius 50 feet. What is its area?

8. The diameter of a circle is 400 feet. cumference?

What is its cir

9. The circumference of a circle is 1256.64 feet. What is its diameter ?

10. How many yards of carpeting 1 yard wide will be required to carpet a room 18 ft. long and 15 ft. 6 in. wide?

11. A room that is 18 ft. 9 in. square requires 50 yards of carpeting. What is the width of the carpeting?

12. How many acres in a field 45 rods long and 48 rods wide?

13. The diameter of a circle is 15 meters. cumference in feet?

What is its cir

14. What is the area of the gable end of a house 32 ft. wide, the ridge being 14 ft. 6 in. higher than the base of the gable?

15. How many hektares in a rectangular meadow 564.50 meters long and 260 meters wide?

16. What will it cost at 60 cents a square yard to concrete a walk 288 ft. long and 12 ft. 6 in. wide?

17. A horse is fastened to a stake by a chain 60 feet long. How many square rods of surface can the chain sweep over?

18. How many square feet of sheet zinc will be required to line a cistern 6 ft. deep, having a square bottom, of which each side is 2 ft. 6 in.?

19. The capitol at Washington is 751 feet long and 348 feet wide. How many acres does it cover?

20. On laying the pavement of a court with stones 2 ft. 6 in. long by 9 in. wide, it is found that it requires 75 stones to form one strip extending the whole length of the court, and that 8 strips will exactly cover it. What is the area in square yards, and what is the cost of the pavement at 20 cents a square foot?

[blocks in formation]
[ocr errors]

21. How many cubic feet in a beam 10 feet long, 1 foot wide, and 1 foot deep? In a beam 10 feet long, 1 foot wide, and 2 feet deep?

22. How many cubic feet in a block of marble 8 feet long, 2 feet wide, and 1 foot thick? In a block 8 feet long, 2 feet wide, and 2 feet thick?

« ΠροηγούμενηΣυνέχεια »