The document RD Sharma Solutions - Ex-19.1 & 19.2, Visualising Solid Shapes, Class 7, Math Class 7 Notes | EduRev is a part of the Class 7 Course RD Sharma Solutions for Class 7 Mathematics.

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**Complete the following table and verify Euler's formula in each case.**

Faces (F) | 6 | 4 | 9 | 7 |

Edges (E) | 12 | 6 | 16 | 15 |

Vertex (V) | 8 | 4 | 9 | 10 |

I | II | III | IV | |

Faces (F) | 6 | 4 | 9 | 7 |

Edges (E) | 12 | 6 | 16 | 15 |

Vertices (V) | 8 | 4 | 9 | 10 |

Euler's formula (F âˆ’ E + V) | 6 âˆ’ 12 + 8 = 2 | 4 âˆ’ 6 + 4 = 2 | 9 âˆ’ 16 + 9 = 2 | 7 âˆ’ 15 + 10 = 2 |

Hence Euler's formula is verified for these figures.

**Give three examples from our daily life which are in the form of (i) a cone (ii) a sphere (iii) a cuboid (iv) a cylinder (v) a pyramid.**

(i) Cone: Ice-cream cone, clown cap, rocket

(ii) Sphere: Football, a round apple, an orange

(iii) Cuboid: book, brick, duster

(iv) Cylinder: circular pipe, glass, circular pole

(v) Christmas decorations, cheese and patio umbrellas.

**Exercise 19.2**

Match the following nets with appropriate solids:

Here

(a) â†’ (ii)

(b) â†’ (iii)

(c) â†’ (iv)

(d) â†’ (i)

**Identify the nets which can be used to make cubes (cut-out the nets and try it):**

Only (ii), (iv) and (vi) form a cube.

**Can the following be a net for a die? Explain your answer.**

Since, in a die, the sum of the number of opposite faces of a die is 7. In the given figure, it is not possible to get the sum as 7. Hence the given net is not suitable for a die.

**Out of the following four nets there are two correct nets to make a tetrahedron. Identify them.**

For making a tetrahedron, only (i) and (iii) are suitable nets.

**Here is an incomplete net for making a cube. Complete it in atleast two different ways.**

The complete nets for making a cube are Images