Calculation note
The Pythagorean theorem is one of the most useful bridges between classroom geometry and practical layout. It turns two perpendicular sides into a diagonal, making it useful for construction set-out, ramps, screens, maps, ladders, drawing checks and distance problems.
The theorem is a square-area statement
The familiar formula a² + b² = c² says that the square built on the hypotenuse has the same area as the two squares built on the legs combined. The calculator keeps that square-sum step visible before taking the square root.
The 3-4-5 triangle is a practical squaring tool
A triangle with legs in the ratio 3 and 4 has a diagonal of 5. Builders and students often use that relationship because it gives a quick check that two measured legs form a right angle.
Print the diagonal with the assumptions
A printable report is useful for homework, timber or tile layout, site notes and drawing checks because it preserves the two legs, calculated diagonal, optional measured diagonal and rounding basis on one page.