A Spinning Top
Part of the Surface Area & Volume section of Coddy's Geometry journey. Lesson 54 of 62.
A part of a solid can need its own chase before it gives a volume. A cone given by its slant height needs its height first, wherever it sits.
This rocket is a cone on a cylinder, both of radius 6, and the cone is given by its slant height 10. Its height comes first: h^2 = 10^2 - 6^2 = 64, so h = 8. Then the cylinder holds pi × 6^2 × 3 = 108×pi and the cone 1/3 × pi × 6^2 × 8 = 96×pi. Together: 108×pi + 96×pi = 204×pi.
Plan before you tap: list what each part needs, find what is missing, then the volumes.
Challenge
A spinning top is a cone standing on a hemisphere, both on the same circle of radius 3. The cone's slant height is 5. Find the volume of each part, then press Check.
Try it yourself
Find the marked part of the figure
This lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Surface Area & Volume
1Solids and Their Parts
Faces, Edges and VerticesPrisms and CylindersPyramids and ConesHeight or Slant Height?Spheres and HemispheresRecap: Parts of Solids4Pyramids
Volume of a PyramidThe Slant HeightHeight From the SlantHeight From the VolumeRecap: Pyramids2Volume of Prisms
Volume of a CuboidVolume of a PrismAny Triangle EndA Missing EdgeRecap: Prism Volume8Surface Area of Cylinders
Unrolling a CylinderHeight From the SurfaceRadius From the SurfaceEnough for the Volume?Recap: Cylinder Surfaces11Mixed Solids
Solids From SolidsA Spinning TopWhich Lengths?Letters in the LengthsRecap: Mixed Solids3Cylinders
Volume of a CylinderHeight From the VolumeRadius From the VolumeEnough to Find It?Recap: Cylinders6Spheres and Hemispheres
Volume of a SphereHalf a SphereRadius From the VolumeSphere in a CylinderRecap: Spheres9Pyramids and Cones Outside
Surface of a PyramidSlant Height FirstSurface of a ConeThe Cone: Slant FirstRecap: Pyramid Surfaces