Short answer
What you need to know
Open the DuckieDai Rectangle Area program page and select Start program in the screen preview. Enter a unit, width, and height to see the prompts and result. This is a browser recreation of the reviewed interaction, not a TI emulator or execution of the downloadable Python source.
Start the browser preview
Open the Rectangle Area program page and find the interactive calculator-screen preview. Select Start program. The screen shows the DuckieDai duck, signature, and opening text before asking for inputs. No calculator, installation, or download is needed for this step.
The preview runs in your browser with JavaScript. If it is unavailable or disabled, you can still read the source and download the reviewed Python file from the same page.
Follow a worked rectangle example
When prompted for a unit, enter cm. Enter 4 for the width and 7 for the height. The area should be 28 cm^2 because 4 cm multiplied by 7 cm is 28 square centimeters. The screen follows the program's prompt-and-answer flow; choose Restart to try different values.
Use the same unit for both dimensions. The program multiplies width by height and labels the result in squared units; it does not convert between different length units for you. Check the program page for accepted units and invalid-input behavior before using other examples.
What the preview proves—and what it does not
The preview lets you explore the order of prompts, opening screen, input validation, and example calculation. It is a visual browser adapter based on the reviewed program behavior. It does not execute the downloadable .py file, emulate TI hardware, or establish compatibility with a particular calculator.
For actual calculator use, read the program page's model, OS, Python App, physical-device review, limitations, and source digest. Then transfer the file using the installation guide and test a known example on your own TI-84 Plus CE Python.
From preview to calculator
If the preview is useful, inspect the complete source and download the reviewed .py file from the Rectangle Area page. TI Connect CE sends it to the calculator as a Python AppVar. You may choose any valid, unique calculator name that helps you remember it; the suggested name is not required.
A browser result is practice, not a substitute for checking the result or following a teacher's, school's, or exam's rules on calculator programs.
Important limitation
Verify important findings
This browser preview is not a TI-Python runtime, hardware emulator, or guarantee that the downloaded file will run on every calculator. Verify the exact model and software versions, and test the transferred program on your device.
Further reading
Authoritative references
These primary sources support the concepts and reference information in this guide. Their inclusion does not imply endorsement of Hidden Word Scanner.