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Surface Area of Pyramids and Cones

  • Pyramids
    • The vertex is the point where all the faces except the base intersect
    • The base is the polygon that connects all the lateral faces
    • Lateral faces always form triangles
    • Lateral edges have the vertex as an endpoint
    • The altitude is the segment from the vertex perpendicular to the base
  • Regular pyramid
    • The base is a regular polygon
    • The endpoints of the altitude is the vertex and the center of the base
    • All the lateral faces are congruent isosceles triangles
    • The slant height is the height of each lateral face
  • Lateral area of a regular pyramid = ½(perimeter of base × slant height)
  • Surface area of a regular pyramid = lateral area + area of the base
  • Cone
    • The base is a circle
    • The axis is the segment whose endpoints are the vertex and the center of the base
    • The altitude is the perpendicular height
  • Lateral area of a right cone = π × radius × slant height
  • Surface area of a right cone = lateral area + area of the circle

Surface Area of Pyramids and Cones

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Mathematics: Geometry