释义 |
subtend /sʌbˈtɛnd /verb [with object]1 Geometry (Of a line, arc, or figure) form (an angle) at a particular point when straight lines from its extremities are joined at that point: the angle subtended by a string of length r at the centre of the sphere...- The radian is a unit which connects the radius of an arc, the length of the arc and the angle subtended by the arc.
- The most common geometry for curved crystal diffraction is based on the Rowland circle principle, which relies on the well-known property of a circle that an arc segment subtends a constant angle for any point on the circle.
- Reticles are in the second focal plane, so as power is changed the angle subtended by the space between lines varies.
1.1(Of an angle or chord) have bounding lines or points that meet or coincide with those of (a line or arc).This allowed him to calculate the chord subtended by angles of 36, 72, 60, 90 and 120....- The Arc, Chord, Radius, Height, Angle, Apothem, and Area Suppose you have a segment of a circle, bounded by an arc of the circle and the chord subtending it.
- In fact Shen demonstrated a remarkable ability to view spatial arrangements and he gave an approximate formula for the length of a circular arc in terms of the chord subtending the arc.
2 Botany (Of a bract) extend under (a flower) so as to support or enfold it: the main beauty is provided by the bracts which subtend the flowers...- All flowers are subtended by a bract and two bracteoles.
- The flower meristems are produced acropetally by the inflorescence meristem and are subtended by bracts.
- The bract immediately subtends the sepal, partly enclosing it.
OriginLate 16th century (in sense 1): from Latin subtendere, from sub- 'under' + tendere 'stretch'. sense 2 dates from the late 19th century. Rhymesamend, append, apprehend, ascend, attend, befriend, bend, blend, blende, commend, comprehend, condescend, contend, defriend, depend, emend, end, expend, extend, fend, forfend, friend, impend, interdepend, lend, mend, misapprehend, misspend, offend, on-trend, Oostende, Ostend, perpend, portend, rend, reprehend, scrag-end, send, spend, suspend, tail end, tend, transcend, trend, underspend, unfriend, upend, vend, weekend, wend |