A free program for Android, by LKMathsApps.
FreeGeo Mathematics is an interactive geometry and algebra app for Android. It contains more than a hundred tools for creating geometric objects and solving algebraic equations. You can do everything with it:
Draw and edit objects like lines, circles, squares, rectangles, conics, angles, and many more. You can move, scale, or rotate an object with your fingers. You can add points, lines, and circles to an object. You can use the tool to calculate the area, perimeter, circumference, diagonal length, and volume of an object. You can use the tool to find the coordinates of a point, line, or circle. You can use the tool to find the intersection of two lines, the angle between two lines, the distance between two points, the area of a region, the perimeter of a region, and the volume of a region. You can find the roots of a function.
