円弧三角計算　FREE is a free Android app developed by エヌケイシステムズ. It falls under the category of Business & Productivity and provides a convenient way to calculate various values related to arcs and triangles.

This app allows users to input known values such as radius, central angle (in DMS or DEG format), chord length, arc length, height, base 1, base 2, and arc height. With the input of any two known values, the app automatically calculates the remaining values. Additionally, when entering the central angle in DMS format, the app displays the converted value in DEG format, and vice versa.

There are a total of 28 input patterns available, allowing users to calculate a wide range of arc and triangle properties. It's important to note that the free version of the app displays advertisements.