Page 279 - Start Up Mathematics_7

8. The adjoining net will fold to form a .

9. A net of a is not possible.

10. If the sum of numbers on the two dice thrown together is 8, then the sum of the numbers
opposite to these faces is .

Answer in One Word or a Line

1. Name a solid having one curved and one flat surface.
2. Name a solid having two edges and no vertex.

3. Give another name for a triangular pyramid.
4. Is cube a polyhedron?

5. How many edges does an octahedron have?
6. What is meant by a net of a solid?

7. How is an oblique sketch different from an isometric sketch?
8. Is an isometric sketch of a solid unique?

9. Can a solid be completely determined, if its three views (i.e., front, side and top) are known?

let’s evaluate

1. Which of these nets will make a square pyramid? Verify by tracing, cutting and folding the
shape.

(a) (b) (c) (d) (e)

2. Draw isometric sketches of the following shapes:

(a) (b)

3. For the given isometric shape answer the following questions:

(a) How many unit cubes are there in this arrangement?

(b) How many unit cubes should be added to get a cuboid of
dimension 5 × 5 × 3?

(c) How many cubes are hidden from your view (i.e., cubes
having no face visible in the given sketch)?
(d) If this shape is painted red on all its faces, how many unit

cubes will have no face coloured?
(e) Draw an oblique sketch of the given shape.

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