Rectangle calculator will help you calculate the diagonal of the rectangle, the side length, height, area of the rectangle.

The calculator is used to test your eyesight and recognize the difference in color shades. After clicking on the first lighter field, the calculator will change colors and the countdown will begin. Each test takes 15 seconds. Search for a lighter field and click on it. Each subsequent test is more difficult. The test will be aborted if you do not give the correct answer within 15 seconds or if you make a wrong choice three times.

Parallelogram calculator will help you calculate the long diagonal of the parallelogram, the short diagonal of the parallelogram, the side length, heights, area of the parallelogram.