Etymologizing Mathematical Terms - From Trigonometry to Geometry to Sine/Cosine/Tangent

Trigonometry from Modern Latin trigonometria (Barthelemi Pitiscus, 1595), from Greek trigonon "triangle" from tri- "three"+ gōnia "angle, corner" + metron "a measure." "branch of mathematics that deals with relations between sides and angles of triangles," Geometry - “a measuring of the earth” from combining form of gē (gaia) "earth, land" + -metria "a measuring of" Geometry is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. Parallel from para- "beside" + allēl "each other." in geometry, of lines, "lying in the same plane but never meeting in either direction." As a noun from 1550s, "a line parallel to another line." Meanings "a comparison made by placing things side by side" and "thing equal to or resembling another in all particulars" are from 1590s.  Parallel bars as gymnastics apparatus is recorded from 1868. Perpendicular - "at right angles to the horizon," from per "thoroughly" (see per) + pendere "to hang, cause to hang; weigh" (from PIE root *(s)pen- "to draw, stretch, spin"). Percent - “by/through a hundred” from Modern Latin per centum "by the hundred" Angle - directly from Latin angulus "an angle, a corner," a diminutive form from PIE root *ang-/*ank- "to bend" (source also of Greek ankylos "bent, crooked," Latin ang(u)ere "to compress in a bend, fold, strangle;" Old Church Slavonic aglu "corner;" Lithuanian anka "loop;" Sanskrit ankah "hook, bent," angam "limb;" Old English ancleo "ankle;" Acute - from Latin acutus "sharp, pointed," figuratively "shrill, penetrating; intelligent, cunning," past participle of acuere "to sharpen" (literal and figurative) It was also used of humors (early 15c.). The meaning "ending in a sharp point" is from 1560s; the sense of "sharp or penetrating in intellect" is from 1580s. i.e. acute injury, acute inflammation, acute pancreatitis Obtuse from Latin obtusus "blunted, dull," also used figuratively, past participle of obtundere "to beat against, make dull," from ob "in front of; against" + tundere "to beat," from PIE *(s)tud-e- "to beat, strike, push, thrust," from root *(s)teu- "to push, stick, knock, beat" In geometry, in reference to a plane angle greater than a right angle." Calculus - from Latin calculus "reckoning, account," originally "pebble used as a reckoning counter," diminutive of calx (genitive calcis) "limestone." In medicine, the word also has been used to refer generally to "concretion occurring accidentally in the animal body," such as dental plaque; dental calculus. Sine - from Latin sinus "fold in a garment, bend, curve, bosom." Cosine “with the fold” “with” + “bend, curve” Tangent - "meeting at a point without intersecting," from Latin tangentem (nominative tangens), present participle of tangere "to touch." Addition - "action of adding numbers." from Latin additionem (nominative additio) "an adding to, addition," noun of action from past-participle stem of addere "add to, join, attach" “The action of” + “joining”