The perimeter of a figure is the sum of all its sides.
To bisect—is to divide into two equal parts.
To trisect—is to divide into three equal parts.
To inscribe—is to draw one figure within another, so that all the angles of the inner figure touch either the angles, sides, or planes of the external figure.
To circumscribe—is to draw a figure round another, so that either the angles, sides, or planes of the circumscribing figure touch all the angles of the figure within it.
LINES, ANGLES, AND FIGURES.
To divide a given right line into two equal parts.
From the extremities of the line as centres, and with any opening in the compasses, greater than half the given line, as a radius, describe arcs intersecting each other above, and below the given line. A line being drawn through these intersections will divide the given line into two equal parts.
An arc of a circle is bisected in the same manner.