Complex sentence: The tomahawk is a tool in geometry consisting of a semicircle and two line segments that may be used for angle trisection (splitting an angle into three equal parts), named for its resemblance to a tomahawk, a Native American axe.
Split into simpler sentences: The tomahawk is a tool in geometry for angle trisection, the problem of splitting an angle into three equal parts. The boundaries of its shape include a semicircle and two line segments, arranged in a way that resembles a tomahawk, a Native American axe.