THE NEW STUDENT'S REFERENCE WORK
A square is a rectangle all of whose sides are equal.
The area of a surface is the number of square units it contains.
Find the area of a rectangle 3 feet long and 2 feet wide.
1 sq. ft. 1 sq. ft. 1 sq. ft.
1 sq. ft. 1 sq. ft. 1 sq. ft.
Since there are 3 sq. ft. in 1 row, in 2 rows there will be 2 X 3 sq. ft. or 6 sq. ft.
Rule for area.
To find the area of a rectangle, multiply the number of square units in one row by the number of rows; or, multiply the units in length by the units in breadth, remembering that the units must be of the same denomination. Inches cannot be multiplied by feet, nor feet by yards.
If the units are different, one must be changed to an equivalent form of the denomination of the other.
EXERCISE 23.
1. A floor measures 18 ft. by 15 ft. How many square feet does it contain? How many square yards?
18
15 270™ 9 = 30 sq. yd.
~90
18
270 sq. ft.
2. A floor measures 24 ft. by 18 ft. How many square yards does it contain!
3. How many square rods in a tract of land 120 rd. long and 40 rd. wide? Find its value at $75 per acre.
4. What is the cost of concreting a walk 25% ft. long and 5 ft. wide at 70c per square yard?
5. How many acres are there in a rectangular field 162 rd. long and ,84 rd. wide?
6. How many paving blocks will be needed to pave a street 1750 ft. long and 40 ft. wide, if it takes 48 blocks to pave a square yard?
7. A swimming tank is 38 ft. long and 18 ft. wide. What will it cost to cement the bottom at $2.35 per square yard?
8. Compare a field 46 rd. long and 38 rd. wide with a 10 acre lot. Which is larger, and how much larger?
