Inscribed angle its intersection points equals half of the central angle subtended by the chord. See also Tangent lines to circles. The inscribed angle theorem is used in many proofs of elementary Euclidean geometry of the plane. A special case of the theorem is Thales' theorem, which states that the angle subtended by a diameter is always 90°, i.e., a right angle. As a consequence of the theorem, opposite angles of cyclic quadrilaterals sum to 180°; conversely, any quadrilateral for which this is true can be inscribed in a circle. As another example, the inscribed angle theorem is the basis for several
Right-angle weave also variations on the basic stich like cubic right angle weave, or CRAW. Seed beads, fire polished beads and crystal beads are common choices in pieces using right-angle weave. This stitch is said to have originated somewhere in Africa, but examples can be found in beadwork from many cultures, including Philippines, New Guinea and England. Bead artists are known to use right-angle weave stitch to cover forms, such as vases, beads and other objects. Right-angle weave Right-Angle weave stitch, also known as RAW, is an off-loom bead weaving technique. Beads are stitched together with thread only making right angle turns,