subtend
verb
sub·tend səb-ˈtend 
subtended; subtending; subtends
transitive verb
1
a
: to be opposite to and extend from one side to the other of
a hypotenuse subtends a right angle
b
: to fix the angular extent of with respect to a fixed point or object taken as the vertex
a central angle subtended by an arc
the angle subtended at the eye by an object of given width and a fixed distance away
c
: to determine the measure of by marking off the endpoints of
a chord subtends an arc
2
a
: to underlie so as to include
b
: to occupy an adjacent and usually lower position to and often so as to embrace or enclose
a bract that subtends a flower
Example Sentences
Recent Examples on the Web Before 1967, political borders, however provisional, subtended cultural ones: sovereignty derived from international recognition and the consent of the governed. 
Bernard Avishai, The New Yorker, 5 June 2017
Bernard Avishai, The New Yorker, 5 June 2017 Word History
Etymology
Latin subtendere to stretch beneath, from sub- + tendere to stretch — more at thin
First Known Use
circa 1560, in the meaning defined at sense 1a