Rectangle / Square
Geometry
Area, perimeter, diagonal; reverse-solve from any two.
Inputs
Results
Frequently asked questions
▶What does the Rectangle / Square do?
The Rectangle / Square is an interactive geometry lab where you change inputs and the answers update live, helping you build intuition without doing the arithmetic by hand.
▶Who should use the Rectangle / Square?
Students from primary to senior secondary classes, parents helping with homework, and anyone revising geometry can use this lab to check answers and explore "what-if" scenarios.
▶Is the Rectangle / Square free to use?
Yes. Every lab on math.suparnpatra.com is free and runs entirely in your browser : nothing is sent to a server.
▶Does the Rectangle / Square work offline?
Once the page is loaded, all calculations run locally in JavaScript, so you can keep using it even on a flaky connection.
▶How accurate are the results?
Results use standard JavaScript double-precision arithmetic and the textbook formula for geometry. We never display scientific notation : numbers are shown as ordinary decimals you can read at a glance.