Shape Calculator

If you need to calculate the area of most simplest shapes but don't remember the formulas,
this application will calculate it for you,
moreover it can calculate the perimeter, angles, diagonals(if available) for a triangle, rectangle, circle, trapezoid, parallelogram and polygon.
All you need to do is to enter the sides of the shape.
The application provides a scroll-view of buttons that allows the user to choose a specific shape in order to calculate its attributes.
The calculations can be preserved/clear for each last calculation of a specific shape.
The user can also specify the numbers' precision of calculation results(by default is 2).