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Page 168 - A cylinder of revolution is a cylinder generated by the revolution of a rectangle about one side as an axis.
Page 177 - TRIANGLE is one in which all the angles ^^^ are acute. \. / The HYPOTENUSE is the side of a right triangle opposite the right angle. The other sides are called the legs. An EQUIANGULAR TRIANGLE is one in which the three angles are equal. The value of each angle is 60°. The BASE is the side on which the triangle is supposed to stand. In an isosceles triangle, the equal sides are called the legs, the other side the base; in other triangles any one of the sides may be called the base. The ALTITUDE...
Page 173 - Polygon of three sides is called a triangle ; one of four sides, a quadrilateral; one of five sides, a pentagon; one of six sides, a hexagon; one of seven sides, a heptagon; one of eight sides, an octagon ; one of ten sides, a decagon ; one of twelve sides, a dodecagon, &c.
Page 169 - Elevation. A drawing made on a vertical plane by means of projecting lines perpendicular to the plane from the points of the object. The terms elevation, vertical projection, and front view all have the same meaning. Ellipse. A plane figure bounded by a line such that the sum of the distances of any point in it, as c, from two given points e and f, called foci, is equal to a given line, as a b. The point midway between the foci is called the center.
Page 175 - RHOMBOID is a parallelogram whose angles are /V oblique angles. * ' A RHOMBUS is a Rhomboid whose sides are equal. / / The side upon which a parallelogram stands and the opposite side are called respectively its lower and upper bases.
Page 175 - RECTANGLE is a quadrilateral whose angles are right angles. A SQUARE is a rectangle whose sides are equal. A RHOMBOID is a parallelogram whose angles are oblique angles.
Page 177 - The following statements apply to any right triangle and are illustrated in the figure below. 1. A right triangle is one in which one of the angles is a right angle (90 degrees). 2. The hypotenuse is the side opposite the right angle. 3. The le"gs of a right triangle are the two sides that form the right angle. 4. The sine of any angle 6 is equal to the side opposite that angle divided by the hypotenuse. 5. The cosine of any angle 6 is equal to the side adjacent...
Page 176 - SURFACE. — The boundary of a solid. It has but two dimensions — length and breadth. Surfaces are plane or curved. A Plane Surface is one upon which a straight line can be drawn in any direction. A Curved Surface is one no part of which is plane. The surface of the sphere is curved in every direction, while the curved surfaces of the cylinder and cone are straight in one direction. The surface of a solid is no part of the solid, but is simply the boundary of the solid.
Page 174 - A regular pyramid is one whose base is a regular polygon and whose vertex lies in the perpendicular erected at the center of the base.
Page 174 - The directrix is the base, and the fixed point (point directrix) is the vertex of the cone. Each position of the generatrix is an element of the surface. The axis is a line connecting the vertex and the center of the base. The altitude is a perpendicular dropped from the vertex to the base. A cone is right if the axis and altitude coincide; it is oblique if they do not coincide. A truncated cone is that portion lying between the base and a cutting plane which cuts all the elements. The...