222 FARM ARITHMETIC. 



807. What is the height of a tree when C D = 6 feet, 

 P A = 30 feet, and P C = 4 feet ? Answer, 45 feet. 



808. What is the height from the ground to the first 

 limb, B, of a tree when the measurements are as follows : 

 C D =z 3' 4", P A = 102' 6" and P C = 7' 2" ? 



To find the number of gallons in a tank or cistern. 



For a rectangular cistern: Multiply together the length, 

 width, and depth in feet and multiply the product by 7.5, 

 the number of gallons in a cubic foot. This will give the 

 contents in gallons. 



809. How many gallons of water in a square cistern 

 4 feet long^ 3 feet wide and 8}^ feet deep ? 



Process : 4 X 3 X 8^ X 7>^ = 750 Gallons. 



For a circular cistern : Multiply the square of the diam- 

 eter in feet by the depth in feet, and this product by 

 5.9. This will give the contents in gallons. 



810. How many gallons of water in a round cistern, 

 the diameter of which is 10 feet and the depth 10 feet? 



Process '. 



10 X 10 X 10 X 5.9 = 5,900 Gallons. 



811. How many gallons of water in a cistern 6 feet 

 long, 6 feet wide, and 6 feet deep ? 



812. How many gallons of water in a circular tank 8 

 feet in diameter and 8 feet deep ? 



813. A farmer wishes to place a square tank 4 feet 

 high in the attic of his house. It must hold 800 gallons. 

 What is the length of the side ? 



814. If the above tank is circular, what must be the 

 diameter? 



The number of bushels in a bin. For a rectangular 

 bin : Multiply together the length, breadth, and depth, each 



