Online Right Triangle Trigonometry Calculator

Solve right triangles instantly with two given values: find missing side lengths, hypotenuse, angles, area, and perimeter using Pythagorean theorem and trigonometric functions.

Right Triangle Diagrama = 3b = 4c = 5α = 36.9°β = 53.1°
Hypotenuse c (c)5
Area (A)6
Perimeter (P)12
Altitude to hypotenuse (h_c)2.4

Trigonometric Ratios (α = 36.87°, β = 53.13°)

ФункціяКут α (36.9°)Кут β (53.1°)Співвідношення сторін
sin (Синус)0.60.8протилежний / гіпотенуза
cos (Косинус)0.80.6прилеглий / гіпотенуза
tan (Тангенс)0.751.3333протилежний / прилеглий
cot (Котангенс)1.33330.75прилеглий / протилежний
sec (Секанс)1.251.66671 / cos
csc (Косеканс)1.66671.251 / sin

How to use

  1. Input any two known values (legs a and b, leg and hypotenuse, or side and acute angle).
  2. Click calculate.
  3. View complete triangle geometry: hypotenuse, angles, perimeter, and surface area.

Trigonometric & Geometry Principles

Pythagorean theorem: c² = a² + b² (where c is hypotenuse, a and b are legs).

Sine ratio: sin(α) = a / c (opposite leg / hypotenuse).

Cosine ratio: cos(α) = b / c (adjacent leg / hypotenuse).

Tangent ratio: tan(α) = a / b (opposite leg / adjacent leg).

Area: S = (a * b) / 2.

Calculation Methodology

A right-angled triangle contains one 90° right angle; complementary acute angles sum up to 90° (α + β = 90°).

Frequently Asked Questions

How many inputs are required to solve a right triangle?

Exactly two known values are required, with at least one being a side length.

How to find hypotenuse length from legs?

Apply the Pythagorean theorem: c = √(a² + b²).

What is the sum of angles in a right triangle?

All triangle interior angles sum to 180° (90° right angle + two complementary acute angles summing to 90°).

How is right triangle area evaluated?

Area is half the product of perpendicular legs: Area = 1/2 * a * b.

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