A sequel to the first six books of the Elements of Euclid, containing an easy introduction to modern geometry, with numerous examples. By John Casey.

BOOK FIRST.
SECTION I.
ADDITIONAL PROPOSITIONS.
IN the following pages the Propositions of the text of
Euclid will be referred to by Roman numerals enclosed
in brackets, and those of the work itself by the Arabic.
The number of the book will be given only when different from that under which the reference occurs.
For the purpose of saving space, the following
symbols will be employed:Circle will be denoted by (
Triangle,, A
Parallelogram,, c!
Parallel,, II
Angle,, Z
Perpendicular,, 1
In addition to the foregoing, we shall employ the
usual symbols of Algebra, and other contractions whose
meanings will be so obvious as not to require explanation.
B