Spheres, cones and pyramids
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The teaching part (1 min) is free to watch. A free account opens the whole lecture: 7 practice questions, 1 real past-paper question with the answer explained, the mistakes that lose marks, the full-marks tip, a one-card summary and a quick quiz.
What this lecture covers
- A scoop of ice cream
- The sphere
Read the transcript of the teaching part
Last time
Before we start: last time, in Perimeter and area of polygons, you learned these points. Here they are again on one card. Keep them in mind, because today builds on them.
A scoop of ice cream
An ice cream cone has a pointed cone of wafer, with a ball of ice cream on top. The ball is a sphere, the wafer is a cone, and the pointed roof of a pyramid-shaped tent is a pyramid. Each has its own formula. The good news: Cambridge prints them on the exam paper. Your job is to pick the right one, and to use it correctly.
The sphere
The volume of a sphere is four thirds pi r cubed. The surface area is four pi r squared. Radius six: four thirds times two sixteen is two eighty-eight. So the volume is two eighty-eight pi, nine hundred and four point seven eight. The surface area is four times thirty-six, a hundred and forty-four pi: four fifty-two point three nine.
How often it comes up
How often Cambridge has asked each part, counted by ExamYard from every past paper in its question bank: Cones, spheres and pyramids.
The whole chapter: Surface Area and Volume.
Chapter 24: Volume and surface area
- Prisms, cuboids and cylinders 5 min
- Spheres, cones and pyramids 6 min
Also for O Level Maths 4024
Which topics come up most in O Level Maths 4024 past papers, counted from every paper since 2004.