goniomeetria

Goniomeetria is the study and practice of measuring angles and the relationships between angles and lengths in geometric figures. In mathematics, it encompasses methods for determining unknown angles in triangles and polygons, as well as the use of trigonometric functions to relate angles to side lengths.

In a broader sense, goniomeetria involves the measurement of angles formed by lines, planes, or vectors. It underpins trigonometry, since the sine, cosine, and tangent functions express ratios that connect angles to side lengths in right triangles and to more complex geometric configurations.

A key instrument in goniometry is the goniometer, a device designed to measure angles. The universal goniometer typically consists of two arms joined at a central pivot and calibrated markings to read angles. Variants include single- and multi-arm devices, as well as inclinometer-based instruments used to measure joint ranges of motion in medical and rehabilitation settings.

Applications of goniomeetria range from theoretical geometry and trigonometry to practical fields such as engineering, drafting, crystallography, and physical therapy. In clinical practice, goniometry is used to assess and document the range of motion of joints, guide treatment decisions, and track progress over time.

The term derives from Greek roots: gonia (angle) and metron (measure), reflecting its historical connection to the measurement of angles and the development of trigonometry.