n 



UNITS OF LENGTH, AREA AND VOLUME 



27 



KXIT. 33. Draw a square foot and a square decimetre and 

 find the number of square decimetres in the square foot, and 

 the fraction which one square decimetre is of one square foot, 



KXPT. 34. If convenient, draw a square yard and a square 

 metre upon a blackboard or a large sheet of paper. Determine 

 the area of the square yard in decimals of a square metre, and 

 the area of the square metre in square yards. To obtain the 

 latter result, the number of square inches in one square metre 

 is determined, and the result divided by the number of square 

 inches in a square yard. 



Relation between British and Metric Units of Area. 



These exercises have shown roughly the relation between the 

 measurements of areas expressed in the metric and British 

 systems of units. The exact proportions which the units of area 

 in the two systems bear to one another are shown in the following- 

 table : 



Metric to British. 



= 0*155 square inch. 

 = 15 '500 square inches. 



10764 square feet. 

 = 1 '196 square yards. 

 = 119 '603 square yards, 



^-fc . A H^-* 



1 square centimetre 

 1 square decimetre 

 1 square metre 



1 are (100 square metres) 



1 hectare (10,000 square metres) = 2 '471 acres, 



British to Metric, 



1 square inch = 6*451 square centimetres. 

 1 square foot = 9*289 square decimetres. 

 1 square yard = 0*836 square metres. 

 1 acre = 10*117 ares. 



1 square mile = 258*989 hectares. 



Determinations of Areas. It has already been- explained 

 that the area of a square 

 or an oblong can be de- 

 termined by dividing the 

 figure into units of area 

 and counting the number 

 of units. Paper can be 

 procured divided into 

 squares of a definite size, 



similar to those repre- 



sented in Fig. 17. By 



B 



Fl - 17. The Area of the Parallelogram 



is thc same as that of the Oblong 



