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Solve right triangles — hypotenuse, area, perimeter.
📐 Pythagorean theorem: a² + b² = c². For right triangles only.
This calculator solves right triangles using the Pythagorean theorem. Given the two legs (a and b), it finds the hypotenuse (c), the area, and the perimeter.
For any right triangle, a² + b² = c², where a and b are the legs and c is the hypotenuse (the side opposite the right angle). This is one of the oldest and most useful results in mathematics, proven over 400 different ways.
The simplest Pythagorean triple is 3-4-5: 3² + 4² = 9 + 16 = 25 = 5². Carpenters use it constantly — measure 3 units along one wall, 4 along the other, and adjust until the diagonal is exactly 5. Then the corner is perfectly square.
The Triangle Calculator lets you figure out triangle calculatorinstantly, without reaching for a spreadsheet or doing the math by hand. Whether you're planning a budget, checking a loan, or working through homework, the tool applies the correct formula behind the scenes and shows the result the moment you enter your numbers.
Unlike a static chart or table, this calculator adapts to your exact inputs. You can adjust any value and see the outcome update in real time, which makes it easy to compare scenarios — for example, "what if the rate were 1% lower?" or "what if I paid an extra $50 a month?"
Common uses: people reach for this tool when they need to find a right triangle solver hypotenuse, pythagorean theorem calculator, solve right triangle area perimeter, or hypotenuse from two sides.
Browser-based tools like this one have a few real advantages over installed software or manual methods:
The Triangle Calculator is based on the following formula:
A = ½ × b × h
Variables: A = Area (square units) b = Base length (units) h = Perpendicular height to that base (units)
Triangle area. b = base length, h = corresponding height.
Worked example: Step 1: b = 12 m, h = 7 m. Step 2: b × h = 12 × 7 = 84. Step 3: A = ½ × 84 = 42. Result: the triangle's area is 42 m².
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