How to use: Solve right triangle problems using Pythagorean theorem (a² + b² = c²). Enter any two of: Side A (one leg), Side B (other leg), or Hypotenuse (longest side opposite right angle). Calculator finds missing side. Examples: Sides 3 and 4 → hypotenuse = 5. Side 5 and hypotenuse 13 → other side = 12. Common Pythagorean triples: 3-4-5, 5-12-13, 8-15-17, 7-24-25. Applications: construction (checking square corners), navigation (distance calculations), engineering (structural supports), carpentry (roof framing), ladder safety (height and distance from wall). Essential for geometry, trigonometry, and practical measurements in building trades.