The handbook of Technical irrigaTion informaTion - Hunter Industries

Handbook of Technical Irrigation InformationHow to Calculate AreasSquare or rectangleArea = L x WL = lengthW = widthA = 90 feet x50 feet= 4,500square feet W=50Ovals or egg shapes(within 5 percent accuracy)Area = 0.8 L x WL = lengthW = width at midpointArea = 0.8 x 60 x 40 feet= 1,920 square feetL=60L=90W=40Irregular shapesFind the length ofthe longest lineacross the area.Every 10 ft alongthe length line,measure thewidth of the areaat right angles tothe length line.Total all widthsand multiplyby 10.32 feet50 feet45 feet17 feetArea = (A + B + C, etc.) x 10= (32 feet + 50 feet + 45 feet + 17 feet) x 10= 144 x 10= 1,440 square feetTriangleArea = 0.5 x B x HB = baseH = heightArea = 0.5 x 125 feet x 75 feet= 4,687 square feetCircle(within 5 percent accuracy)Area = 0.8 D2D = diameterArea = 0.8 x 50 feet x 50 feet= 2,000s square feetR=30Unusual shapesDivide the area into sections of regular geometric shapes,calculate the area of each section, then total:H=75B=125TrapezoidArea = 0.5 x (A + B) x HA = one parallel sideB = second parallel sideH = height perpendicular to parallel sidesArea = 0.5 x (50 feet + 70 feet) x 30 feet= 0.5 x 120 feet x 30 feet= 1,800 square feetA=50H=30Area of triangle+ Area of rectangle+ Area of one-half of circle= Total areaCircleArea = πr 2π = 3.14R = radiusArea = 3.14 x(30 feet x30 feet)= 2,826 square feetB=70R=3024