trisecting the angle
...that trisecting the angle is one of the three impossible tasks using classical ruler-and-compass construction?
...that <b id="mwAfo"><a class="mw-redirect" href="./Trisecting_the_angle" id="mwAfs" rel="mw:WikiLink" title="Trisecting the angle">trisecting the angle</a></b> is one of the three impossible tasks using classical <a class="mw-redirect" href="./Ruler-and-compass_construction" id="mwAfw" rel="mw:WikiLink" title="Ruler-and-compass construction">ruler-and-compass construction</a>?