Line segmentIn geometry, a line segment is a part of a straight line that is bounded by two distinct end points, and contains every point on the line that is between its endpoints. The length of a line segment is given by the Euclidean distance between its endpoints. A closed line segment includes both endpoints, while an open line segment excludes both endpoints; a half-open line segment includes exactly one of the endpoints. In geometry, a line segment is often denoted using a line above the symbols for the two endpoints (such as ).
Four-dimensional spaceFour-dimensional space (4D) is the mathematical extension of the concept of three-dimensional space (3D). Three-dimensional space is the simplest possible abstraction of the observation that one needs only three numbers, called dimensions, to describe the sizes or locations of objects in the everyday world. For example, the volume of a rectangular box is found by measuring and multiplying its length, width, and height (often labeled x, y, and z).
RamieRamie (pronounced: ˈreɪmi, ; from Malay ), Boehmeria nivea, is a flowering plant in the nettle family Urticaceae, native to eastern Asia. It is a herbaceous perennial growing to tall; the leaves are heart-shaped, long and broad, and white on the underside with dense, small hairs—this gives it a silvery appearance; unlike stinging nettles, the hairs do not sting. The true ramie or China grass is also called Chinese plant or white ramie. A second type, known as green ramie or rhea, is believed to have originated in the Malay Peninsula.
