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 == 3' 4", P A = 102' 6" and P C = T 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 



