Measurement of Area and Volume 



37 



usually termed the " base " and multiply it by the 

 length of the edge of any one rectangular face which 

 is perpendicular to the base. This latter length is 

 called the " height " of the prism. 



2. The Cylinder. This is really a rectangular 

 prism with a circular base. Its volume is also found 

 by multiplying the area of the circular base by the 

 height of the cylinder. In this case the height is 

 found by measuring the length of any straight line on 

 the surface of the cylinder perpendicular to the base. 



Fig. 14. Kg. 15. 



3. The Sphere. The volume of a sphere may be 

 found by multiplying the cube of its radius by JTT. 



4. The Pyramid. Multiply the area of the base 

 by the height, i.e. the length of the perpendicular 

 from the apex upon the plane containing the base, 

 and divide the product by 3. 



5. The Cone. This is simply a pyramid with a 

 circular base, and the rule given above applies. 



To facilitate the solution of problems dealing with 

 the volumes of the above solids, the following formulae 

 may be of service : 



