Right Triangle - Unknown Side using Tangent

\[opposite=adjacent\tan(\theta)\]

opposite = length of the opposite side (m)

adjacent = length of the adjacent side (m)

theta = known angle of the right triangle (rad or °)

This trigonometric formula calculates the opposite side of a right triangle using the tangent ratio.

The tangent function relates the opposite side of an angle to its adjacent side.

It is one of the primary trigonometric relationships used in geometry, engineering, physics, and surveying.

Use this formula when:

- The adjacent side is known

- One acute angle is known

- The opposite side must be calculated

- Solving right triangle problems

- Working with elevations, slopes, or inclinations

The angle may be expressed in degrees or radians depending on the calculator configuration.

If:

adjacent = 20 m

theta = 25°

Then:

opposite = 20*tan(25°)

opposite ≈ 9.33 m

- Trigonometry and geometry

- Construction and engineering

- Surveying and navigation

- Physics calculations

- Terrain slope analysis

- Vector decomposition

Download the fCalc app to calculate this formula and thousands more:

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