Skip to Calculator
Pythagoras²Equation Solver
The Precision Geometry Engine•a² + b² = c²

Pythagoras Equation Solver

Calculate missing sides, angles, exact radicals, area, and altitude with real-time dynamic geometry diagrams and full step-by-step mathematical proofs.

Live Proportional SVGExact Radical (√) & DecimalPythagorean Triples Finder3D Space Diagonal & Distance

Enter Any Two Known Values

Leave unknown sides empty. The solver calculates everything in real-time.

Opposite Angle α
cm
Adjacent to α
cm
Opposite 90°
cm
Optional: Or solve with Angle α or Area
Quick Benchmark Presets:
Proportional SVG Geometry
C (90°)A (α ≈ 36.9°)B (β ≈ 53.1°)a = 3b = 4c = 5
Triangle Solver • Area (A): 6 cm²
Hypotenuse c
5 cm
5
Leg a
3 cm
α ≈ 36.87°
Leg b
4 cm
β ≈ 53.13°
Area (A)
6
½ · a · b cm²
Perimeter (P)
12
a + b + c cm
Altitude (h_c)
2.4
(a·b)/c cm

Full Step-by-Step Mathematical Derivation

Clear proofs and exact radical conversions suitable for homework and exams.

1

1. Identify the Pythagorean Theorem Formula

Formula: c² = a² + b² ⇒ c = √(a² + b²)

Substitution: c = √(3² + 4²)

Computation: c = √(9 + 16) = √(25)

➔c = 5 cm

Note: The hypotenuse c is the longest side, directly opposite the 90° right angle.

2

Calculate Acute Angles α and β

Formula: α = arcsin(a / c), β = 90° - α

Substitution: α = arcsin(3 / 5)

Computation: α = arcsin(0.6)

➔α ≈ 36.87°, β ≈ 53.13°
3

Calculate Area & Perimeter

Formula: Area = ½ · a · b, Perimeter = a + b + c

Substitution: Area = ½ · 3 · 4, P = 3 + 4 + 5

Computation: Area = 6 cm²

➔Perimeter = 12 cm, Area = 6 cm²
Fundamental Mathematical Law

What is the Pythagoras Equation?

The Pythagoras Equation (commonly known as the Pythagorean Theorem) is a cornerstone of Euclidean geometry establishing a fundamental relationship between the three sides of any right-angled triangle. It states that:

a² + b² = c²

Where a and b are the lengths of the two legs adjacent to the 90° right angle, and c is the length of the hypotenuse directly opposite the right angle.

Geometrically, this implies that if you construct squares on each of the three sides of a right triangle, the area of the square built on the hypotenuse is exactly equal to the combined areas of the squares built on the other two legs.

The 3 Primary Pythagoras Rearrangements

1. Solve for Hypotenuse (c)
c = √(a² + b²)

Used when both perpendicular legs (a and b) are known. Always results in the longest side of the triangle.

2. Solve for Leg (a)
a = √(c² - b²)

Used when hypotenuse c and base leg b are known. Requires c > b.

3. Solve for Leg (b)
b = √(c² - a²)

Used when hypotenuse c and vertical leg a are known. Requires c > a.

Interactive Geometric Rearrangement Proof

Interactive Geometric Rearrangement Proof

Visual proof showing that hypotenuse square c² equals leg squares a² + b².

Quick Benchmark Presets:
Adjust Leg a = 3a² = 9
Adjust Leg b = 4b² = 16

Arrangement 1: The Hypotenuse Square (c²)

Total Square Area = (a + b)² = (3 + 4)² = 49

The 4 corner triangles consume 4 × (½ · 3 · 4) = 24. The inner tilted square has area c² = 25.

Conclusion: Unshaded Area 1 = Unshaded Area 2 ⇒ c² = a² + b²

c² = 25

Secondary Geometric Calculations for Right Triangles

Once the three side lengths are established via Pythagoras, our solver instantly computes every associated trigonometric and Euclidean metric:

Triangle Area (A)A = ½ · a · b

Half the product of the two perpendicular legs.

Perimeter (P)P = a + b + c

The total boundary distance surrounding the triangle.

Altitude to Hypotenuse (h_c)h_c = (a · b) / c

The perpendicular distance dropped from vertex C to side c.

Incircle Radius (r)r = (a + b - c) / 2

The radius of the largest circle that fits completely inside.

Special Right Triangles Ratios

Standardized geometry exams frequently leverage special angle relationships that produce exact radical side ratios:

Triangle TypeInternal AnglesSide Length RatioHypotenuse Formula
Isosceles Right45° - 45° - 90°1 : 1 : √2c = leg · √2
30-60-90 Right30° - 60° - 90°1 : √3 : 2c = 2 · (short leg)

Frequently Asked Questions About the Pythagorean Theorem

The Pythagorean Theorem states that in any right-angled triangle, the square of the hypotenuse (the side opposite the 90° angle) is equal to the sum of the squares of the other two sides: a² + b² = c². When solving for the hypotenuse, the formula is c = √(a² + b²). When solving for a missing leg, the formula is a = √(c² - b²) or b = √(c² - a²).