the angles of Triangles
Let there be a Corrollary to some Prop. Declaring that
a Triangle cannot have more than one obtuse angle,
also that a Triangle cannot have more than one right
angle from which it will follow that every Triangle
must have 2 acute angles. These may be given for
the reason for calling those Triangles that have, one
right angle right angled, those that have one obtuse,
obtuse angled and those that have three acute,
Where a definition can not be had we must be content
with a description.
the exteriour angles
of a Square.
If the sides of a square any square angled Figure be produced the exteriour angles which they
the produced parts make with each other shall be right angles.
A Figure must have as many sides as it has angles and
In description of species of Figures first state the
several diff that can happen determining
the species and then give names to each.
enumerated When a Term is defined write all those that are synonimous
which are used by any Geometrician.
Oblique Triangles are such as have no right angle
the species of these are acute orand obtuse.
N3 equilateral Triangles need be acute.
right lined Figures
Many other right lined figures may be called
regular besides those mentioned by Euclid
for example the opposite boundaries of a trapezium
may be equal and yet not parallel
butand in such figures the angles |^^^| at the correspondent
ends of opposite boundaries may be equal or &c.
Trapezium should be the highest Genus of all
four sided figures Parallelogram a Species
rectangle, rhombus &c a species of parallelogram.
Identifier: | JB/135/022/002
"JB/" can not be assigned to a declared number type with value 135.
sir samuel bentham
[[watermarks::gr [with crown] [britannia motif]]]