Sheraton, Thomas; Bensley, Thomas; Mathews, James; Bensley, Thomas [Bearb.]; Mathews, James [Bearb.]; Terry, George [Bearb.]; Jordan, Jeremiah Samuel [Bearb.]; Wayland, L. [Bearb.]: The Cabinet-Maker And Upholsterer's Drawing-Book: In Three Parts (London: Printed For The Author, By T. Bensley; And Sold By J. Mathews ... C. Terry ... J.S. Jordan ... L. Wayland ... And By The Author, 1793)

C 47 )
All other triangles are of the acute kincL
An obtufe * angle is one that is greater than ninety de-
grees, or more than what we call a fquare, as a line from 9 to
the point D, Fig. 12-
An acute angle is lefs than ninety degrees, as a line front
9 to 10, confidering the fide 9 A as their bafe-
No. 10. This triangle is called Ifofceles, becaufe two of its
fides are equal in length, as G 0, G 0, Fig. 16; or if the fedtor be
opened, a triangle of this kind is fitly reprefented by it.
Thefe four triangles, being bounded by three right lines,
are called rectilineal plain triangles; and in general, thefe are
placed before the quadrilateral, or four-fided figures, becaufe
by geometricians they are confidered as more fimple, having
only three fides: but as triangles generally appear more out of
the way to workmen, I have aflumed this liberty to place them
after four-fided figures.
Of mixed Tri angles.
Of this kind are numbers 11,12,13,14, and they are called’
mixed triangles, becaufe fome of their fides are right lines, and
Obtufe flgnifies flat or blunt, and acute /harp or cutting,
fome