Pythagorean Theorem & Trigonometry Calculator

Calculate sides, angles (α, β), area, perimeter, height hc, and hypotenuse segments (p, q) in a right triangle. Features interactive geometric square proof (a² + b² = c²) and step-by-step trainer.

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📐Gegebene Dreiecksgrößen auswählen

Wähle zwei bekannte Größen aus, um alle Seiten, Winkel, Höhen und Flächen zu berechnen.

Beispiele:
📐Interaktive Geometrie des rechtwinkligen Dreiecks
a² = 9.0b² = 16.0c² = a² + b² = 25.0a = 3.00b = 4.00c = 5.00A (α = 36.9°)B (β = 53.1°)C (90°)
Kathete a
Kathete b
Hypotenuse c (a² + b² = c²)
Hypotenuse c
5,000
c = √(a² + b²)
Flächeninhalt A
6,000
A = ½ · a · b
Winkel α / β
36.87° / 53.13°
α + β = 90°
Höhe hc
2,400
hc = (a · b) / c

📊Trigonometrische Kennwerte (Winkelfunktionen)

Sinus (sin α = a / c)
0,6000
Kosinus (cos α = b / c)
0,8000
Tangens (tan α = a / b)
0,7500

📝Ausführlicher Rechenweg & mathematische Begründung

Schritt 1: Hypotenuse c mit Satz des Pythagoras berechnen

Da beide Katheten gegeben sind, gilt $c^2 = a^2 + b^2 \implies c = \sqrt{a^2 + b^2}$:

c=32+42=9+16=25=5c = \sqrt{3^2 + 4^2} = \sqrt{9 + 16} = \sqrt{25} = \mathbf{5}
Schritt 2: Winkel α und β über Trigonometrie (Tangens) ermitteln

Der Tangens von $\alpha$ ist Gegenkathete durch Ankathete: $\tan(\alpha) = \frac{a}{b}$:

tan⁡(α)=34  ⟹  α≈36,87∘,β=90∘−α≈53,13∘\tan(\alpha) = \frac{3}{4} \implies \mathbf{\alpha \approx 36,87^\circ}, \quad \mathbf{\beta = 90^\circ - \alpha \approx 53,13^\circ}
Schritt 3: Höhe hc, Hypotenusenabschnitte p & q, Fläche & Umfang

Berechnung von Höhe $h_c = \frac{a \cdot b}{c}$, Kathetensatz $p = \frac{a^2}{c}, q = \frac{b^2}{c}$ sowie Fläche $A = \frac{1}{2}ab$:

hc=3⋅45=2,4,p=1,8,q=3,2,A=6,U=12h_c = \frac{3 \cdot 4}{5} = \mathbf{2,4}, \quad p = \mathbf{1,8}, \quad q = \mathbf{3,2}, \quad A = \mathbf{6}, \quad U = \mathbf{12}

Historical Origin & The Challenge Solved

Why was this mathematics developed, where does it come from, and what real-world problem did it solve?

📜
Epoche & ZeitalterAncient Babylon, Egypt & Greece (c. 1800 – 500 BCE)
Pioniere: Babylonian Builders, Egyptian Rope-Stretchers (Harpedonaptai), Pythagoras of Samos

1. Boundary Disputes after Nile Floods

Annual Nile floods washed away agricultural field boundaries in ancient Egypt. Land surveyors needed a fast, indisputable method to establish true 90-degree right angles across vast flat terrain.

2. The 12-Knot Rope & a² + b² = c²

Surveyors used a looped rope with 12 equidistant knots. Arranged in a 3:4:5 ratio, it formed a perfect right angle. Pythagoras later formulated and proved the universal theorem for all right-angled triangles.

3. 3D Graphics, GPS & Space Navigation

Euclidean distance calculations in 3D gaming (raytracing), mobile GPS triangulation, and spatial sensor networks operate directly on the Pythagorean theorem.

„Number rules the universe.“ — Pythagoras of Samos

Praxisnutzen & Reale Anwendungsfälle

Warum lernen wir das? So wird diese Mathematik in Wirtschaft, Technik, Wissenschaft und Alltag praktisch angewendet:

Construction & Carpentry

Squaring Corners (3-4-5 Rule)

Builders and carpenters use Pythagorean triples (e.g. measuring 3 ft, 4 ft, and checking 5 ft diagonal) to set perfect 90° right angles.

Praxis-Beispiel:

Aligning building foundations, framing walls, or laying tile flooring.

Surveying & Navigation

Height & Distance Triangulation

Land surveyors calculate mountain peaks and inaccessible building heights using angle measurements and trigonometric ratios.

Praxis-Beispiel:

Calculating antenna tower heights from elevation angle and base distance.

Game Development & 3D Graphics

Euclidean Distance & Vectors

Game engines calculate 2D and 3D Euclidean distances and vector lengths continuously using the Pythagorean formula.

Praxis-Beispiel:

Collision detection between characters using d = √((x2-x1)² + (y2-y1)²).

Mathematical Foundations: Pythagorean Theorem & Trigonometry

The Pythagorean theorem states that in any right-angled triangle, the sum of the squares of the catheti (legs) equals the square of the hypotenuse: a² + b² = c², where c is the longest side opposite the 90° angle.

Right-triangle trigonometry defines sine, cosine, and tangent as ratios of sides: sin(α) = opposite / hypotenuse = a / c, cos(α) = adjacent / hypotenuse = b / c, and tan(α) = opposite / adjacent = a / b.

The theorem is complemented by Euclid's geometric theorems: the geometric mean theorem (altitude theorem hc² = p · q) and the leg theorems (a² = c · p and b² = c · q), where p and q are the projections of legs onto the hypotenuse.

Frequently Asked Questions (FAQ) about Pythagoras & Trigonometry

When can the Pythagorean theorem be used?

The Pythagorean theorem applies only to right-angled triangles (one angle exactly 90°). For non-right triangles, the Law of Cosines c² = a² + b² - 2ab·cos(γ) must be used.

What are Pythagorean triples?

Pythagorean triples are integer side lengths (a, b, c) that satisfy a² + b² = c². Well-known examples include (3, 4, 5), (5, 12, 13), and (8, 15, 17).

How are sine, cosine, and Pythagoras related?

Directly from the theorem comes the fundamental trigonometric identity: sin²(α) + cos²(α) = 1 for any angle α.