Track quiz
Show on a big screenEight ideas, eight checks. The table comes first.
| Idea | How it goes |
|---|---|
| Skin by net | Six faces, added: 2 × (lb + bh + hl). |
| Filling in cubes | l × b × h counts unit cubes. |
| Two growth stories | Every edge × k: skin × k², filling × k³. |
| A tin unrolled | The label is 2πr long. Volume is πr²h. |
| The cone | l = √(r² + h²). Volume is ⅓πr²h. |
| Round solids | Sphere: 4πr² and 4/3 πr³. |
| The pyramid | Volume ⅓ × base × h. Walls use the slant. |
| Job picks measure | Covers wants cm². Fills wants cm³. A rope wants cm. |
A closed box is 10 cm by 8 cm by 4 cm. What paper covers it?
A cube has edge 5. A second cube has edge 10. Compare their volumes.
A tin has radius 7 cm and height 10 cm. What area does its curved side cover?
A cone has radius 6 cm and height 8 cm. What is its slant height?
A cylinder holds 90 cm³. A cone has the same base and the same height. What does the cone hold?
A sphere of radius 21 cm is cut through its centre. What is each half's total surface?
A square pyramid is 4 m high. Its base has side 6 m. How much canvas do the walls need?
A drum gets a coat of paint. Later it is filled with oil. What answers does that need?
The Class 9 syllabus also covers surface area and volume. Its two questions are what covers a solid, and what fills it.
Next: Statistics. This track measured solids in space. That track turns a heap of numbers into one honest summary.
Reveal every answer to finish this lesson.