Thereâs really no way to say exact costs for sure but here in the DC area, youâre most likely starting at $5,000-10,000 for a smaller backyard pond and going up from there. One like the pond above â where we brought in literally dozens of truckloads of soil and stone â would be well north of $30,000-40,000.
In 1706 (a fruitful year for Pi), Machin found this rapidly converging formula for its calculation: Ï/4 = 4 x arctan (1/5) - arctan (1/239). Also in 1706, the Welshman, William Jones, became the first person to use the Greek letter Ï as an abbreviation for the periphery of a circle with unit diameter. Euler adopted the symbol, and it quickly became the standard notation for Pi in all mathematical contexts.
The number pi, represented by the symbol Ï, is used in everyday life to calculate the radius or circumference of circles and in design and construction. Pi is an irrational number, often approximated to 3.14, that was discovered by Greek mathematicians as a ratio to relate the diameter of a circle to the circumference. Continue Reading.