Playfair cipher online encoder and decoder. Encrypt and decrypt any cipher created in a Playfair cipher.

Rectangular trapezoid calculator will help you calculate the long diagonal of the trapezoid, the short diagonal of the trapezoid, the side length, height, area and perimeter of the trapezoid.

With the COSINE Trigonometric Calculator you can calculate the values of any cosine function. In addition to the response results, the calculator will also plot the selected function. You can choose one of the preset functions, e.g. cosine, cos ² - cosine square, arccos - arccosine, cosh - hyperbolic cosine, arcosh - function inverse to cosh, you can also enter your own function, e.g. cos(x ) * cos(x) * cos(x) for cos³(x), cos(2x), cos(x+3), cos(x^2) etc.