Mr. Carter even, who by this time had become cemented in a warm trilateral friendship with Father Barney and the Rev.
"Castle Richmond"
Anthony Trollope
21. Further, of trilateral figures, a right-angled triangle is that which has a right angle, an obtuse-angled triangle that which has an obtuse angle, and an acute-angled triangle that which has its three angles acute.
"The Teaching of Geometry"
David Eugene Smith
Behind the column which still commemorates "the great battle" of that day, stretches now a trilateral patch of pasture-land, which faces a small house.
"The Last Of The Barons, Complete"
Edward Bulwer-Lytton