Elements of astronomy ... with explanatory notes, and questions for examination (1855)
Brocklesby, John, 1811-1889 · New York, Farmer, Brace & co. · leaf 27
A RECTILINEAR TRIANGLE. A RECTILINEAR RIGHT-ANGLED TRIANGLE. tres, meaning three. The sum of the three angles of anyrectilinear1 triangle is always equal to 180°. Fig. 4 rep-resents any such triangle, and the sum of its angles isequal to 180° A right-angled rectilinear triangle is onethat contains…
Astronomy
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
