Page 278 - Start Up Mathematics_7

9. Which of the following is not a net
of the square pyramid shown in the
adjacent figure?

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

10. A horizontal cross-section of the solid
shown in the adjoining figure is a:
(a) triangle (b) square
(c) hexagon (d) octagon

11. A solid having only 1 vertex is a:
(a) prism (b) pyramid (c) cylinder (d) cone

solve Mentally
True or False

1. The shadow of a 3-D object is 2 dimensional.

2. The net of a solid is unique.
3. If a right-angled triangle is revolved around one of its legs, a cone is generated.
4. A cylinder has 2 faces.

5. In an isometric sketch, line segments of different lengths can represent the sides of a cube.
6. A cube can cast a shadow of a hexagon.

7. In an oblique sketch, the size of opposite faces must be different.
8. The front, side and top view of a sphere are different.

9. Two solids having same surface area and volume can have different shapes.
10. The given net is of a closed cone.

Fill in the Blanks

1. The base of pyramid is a and its other faces are
having a common vertex.
2. The two faces of a solid meet to form an .

3. A point where three or more faces meet is called a .
4. A solid that has congruent and parallel polygons as top and base joined by rectangular faces
is known as .

5. A solid having no vertex and no edge is a .
6. A pyramid having 4 equilateral triangles as its faces is called a .

7. A polyhedron having 20 faces and 12 vertices will have edges.

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