Triangle Calculator Pythagoras vs Pythagoras Interactive

Solve any right triangle from two values – and any other triangle from three. RIGHT TRIANGLES (FREE) Enter any two of: leg a, leg b, hypotenuse c, angle α or angle β (at least one side). Triangle Calculator finds every missing side and angle, plus the area, perimeter and height to the hypotenuse, using the Pythagorean theorem and sine, cosine and tangent. Swap the legs with one tap; a check confirms α + β = 90°. ANY TRIANGLE Enter any three values – sides a, b, c and angles A, B, C – and solve SSS, SAS, ASA, AAS and the ambiguous SSA case. Every missing side and angle and the triangle type (acute, right, obtuse; equilateral, isosceles, scalene) are free. Pro adds area, perimeter, all three heights, inradius, circumradius and the second SSA solution. VALUES ON THE DRAWING The triangle is redrawn to the true proportions of your answer, with every value written right on it. Prefer a list? Switch to the Classic layout in Settings. SEE HOW IT'S SOLVED Each result comes with its formula and your numbers, for example c = √(3² + 4²) = 5. DEGREES, MINUTES, SECONDS (PRO) Type and read angles like 36°52′12″ – for plans, surveying and job-site work. CLEAR, HONEST ANSWERS The app tells you when values can't form a triangle – a hypotenuse shorter than a leg, sides that break the triangle inequality, or angles that add up to too much – instead of returning a wrong number. FORMULA LIBRARY & HISTORY A searchable library of right-triangle and any-triangle formulas with worked examples, and a history of your calculations to reopen any time (free keeps your last 5). EVERYWHERE YOU WORK iPhone, iPad and Mac, portrait or landscape, light or dark mode – in English, German, Japanese, Turkish, Spanish, French, Italian and Russian. On iPad and Mac: a sidebar, a full-height drawing and keyboard shortcuts. TRIANGLE CALCULATOR PRO • No ads • Full Any Triangle results: area, perimeter, heights, radii and both SSA solutions • Every step of every solution • Angles in degrees, minutes and seconds • Unlimited history and Copy All The right-triangle solver and every side and angle of any triangle are always free. Pro options and prices are shown in the app. Terms of Use: https://monsware.com/right-triangle-terms Privacy Policy: https://monsware.com/right-triangle-privacy

Eureka! An interactive illustration of the Pythagorean Theorem. Drag the legs of the right triangle and watch the three squares transform in real time. Every side shows its length, every square its area — in radical form when needed, so you'll see 2√2 rather than 2.828. Slide through a visual demonstration of Euclid's original proof from Book I of the Elements. Understand why the theorem is always true, not just what it claims.