...a circle ; since the cone formed, as above described, is a right cone, and every section of a right cone, made by a plane parallel to the base, is a circle. When, however, the circle is oblique to the plane of projection, the cone formed by the visual rays...

...a circle ; since the cone formed, as above described, is a right cone, and every section of a right cone, made by a plane parallel to the base, is a circle. When, however, the circle is oblique to the plane of projection, the cone formed by the visual rays...

...a circle ; since the cone formed, as above described, is a right cone, and every section of a right cone, made by a plane parallel to the base, is a circle. When, however, the circle is oblique to the plane of projection, the cone formed by the visual rays...

...a circle ; since the cone formed, as above described, is a right cone, and every section of a right cone, made by a plane parallel to the base, is a circle. When, however, the circle is oblique to the plane of projection, the cone formed by the visual rays...

...NOP — BCD, &c. The polygons are therefore similar, by art. 169. 378. Corollary. The section of a cone made by a plane parallel to the base is a circle. 379. Corollary. If the perpendicular ST is let fall from S upon the base, meeting the section at R,...

...from them. Let the circle A в c be the base and p Q the axis of a cone, and let the circle DEF be a section of the cone made by a plane parallel to the base ; also let the circle G н к be another section likewise parallel to the base, and at equal distances...

...C, JVOP = B CD, &c. The polygons are therefore similar, by i5 170. 378. Corollary. The section of a cone made by a plane parallel to the base is a circle. Equivalent Pyramids and Cones. 379. Corollary. If the perpendicular ST is let fall from S upon the...

...we should find Therefore the polygons GI and BD are similar (II. 19). 40. Corollary. A section of a cone made by a plane parallel to the base is a circle. THEOREM VIII. 41 1 The convex surface of a right pyramid is equal to the perimeter of its base multiplied...

...— IH:DC, &c. Therefore the polygons GI and BD are similar (II. 19). 40, Corollary. A section of a cone made by a plane parallel to the base is a circle. THEOREM VIII. 41 i The convex surface of a right pyramid is equal to the perimeter of its base multiplied...

....'. the section SBD is a A. § 446 QE o. PROPOSITION XXIII. THEOREM. 656. Every section of a circular cone made by a plane parallel to the base is a circle. S Let the section abe of the circular cone SA BC be parallel to the base. We are to prove that abc...