Right Triangle Trigonometry Calculator
This specialized trig calculator solves right triangle dimensions and trigonometric ratios from a single acute angle and one known side. Construction crews, survey teams, and physics students rely on these exact calculations when converting slope angles into reachable heights or projecting diagonal braces.
What This Tool Measures
- Sine (sin θ): opposite side divided by hypotenuse
- Cosine (cos θ): adjacent side divided by hypotenuse
- Tangent (tan θ): opposite side divided by adjacent side
By entering one angle (other than the 90° right angle) and a known side, the calculator derives the remaining sides with these identities. Because each ratio depends on precise degree input, using the same units for all side lengths keeps the solution physically accurate.
How to Use the Calculator
- Enter the acute angle between the adjacent side and the hypotenuse in degrees.
- Select whether you measured the adjacent side along the base, the opposite vertical rise, or the hypotenuse.
- Input the measured length using any consistent unit (meters, feet, etc.).
- Click Calculate Triangle to see the remaining side lengths and the sine, cosine, and tangent values.
Realistic Example
A roofer measures a 38° angle from the attic floor (adjacent side) to the ridge beam and knows the base span is 12 meters. Using the tangent relationship, the rise is 12 × tan(38°) ≈ 9.4 meters. The diagonal ridge brace equals 12 ÷ cos(38°) ≈ 15.2 meters. Entering these numbers verifies the same outputs inside the calculator, ensuring the rafters are cut to the correct length.