Carpentry for Boys / In a Simple Language, Including Chapters on Drawing, Laying Out Work, Designing and Architecture With 250 Original Illustrations

by James Slough Zerbe

164. Gnome.—The space included between the boundary lines of two similar parallelograms, the one within the other, with an angle in common.

165. Hyperbola.—A curve, A, formed by the section of a cone. If the cone is cut off vertically on the dotted line, A, the curve is a hyperbola. See Parabola.

167. Hypothenuse.—The side, A, of a right-angled triangle which is opposite to the right angle B, C. A, regular triangle; C, irregular triangle.

168. Incidence.—The angle, A, which is the same angle as, for instance, a ray of light, B, which falls on a mirror, C. The line D is the perpendicular.

169. Isosceles Triangle.—Having two sides or legs, A, A, that are equal.

170. Parabola.—One of the conic sections formed by cutting of a cone so that the cut line, A, is not vertical. See Hyperbola where the cut line is vertical.

171. Parallelogram.—A right-lined quadrilateral figure, whose opposite sides, A, A, or B, B, are parallel and consequently equal.

172. Pelecoid.—A figure, somewhat hatchet-shaped, bounded by a semicircle, A, and two inverted quadrants, and equal to a square, C.