• This was published in 1225 where Fibonacci considers indeterminate problems reminiscent of Diophantus and analyzes problems with methods employed by Euclid. In addition, Fibonacci is recognized for taking the equation \(10x^+2x^2+x^3=20\) and producing an accurate approximation to a root of this equation. He goes on an proves that the root of this equation is not an integer, a fraction nor a square root of a fraction. Without any explanation of his methods used, he approximates the solution and converts it to a decimal which is one of his most remarkable achievements.