the.com/protractor
a half-moon of plastic that taught millions to measure anger in degrees
means A flat, usually semicircular instrument marked in degrees, used to measure and draw angles.
from From Latin protractus, the past participle of protrahere, "to draw forth or drag out" — pro- "forward" plus trahere "to pull" (the same root that gives us tractor and traction). It first meant simply one who or that which draws out, and by the 17th century the geometer's angle-measuring tool had pulled the name to itself.
- origin
- named from Latin for 'drawing out' or extending
- sailing past
- navigators used them to plot ship courses for centuries
- full circle
- the 360-degree version is called a protractor too
- survival rate
- almost none leave geometry class unbroken
for instance
jaxa's akari satellite — infrared space telescope with protractor-like angular measurement capabilities, launched 2006
uss protractor — u.s. navy minesweeper ship commissioned 1953