AP State Syllabus AP Board 7th Class Maths Solutions Chapter 14 Understanding 3D and 2D Shapes InText Questions and Answers.

## AP State Syllabus 7th Class Maths Solutions 14th Lesson Understanding 3D and 2D Shapes InText Questions

Question 1.

Estimate the number of cubes in the following arrangement. (Page No. 273)

Solution:

4 × 3 × 2 = 24 No. of cubes in the above fig. = 24

3 × 2 + 2 = 6 + 2 = 8

No. of cubes in the above fig. = 8

3 + 2 + 2 + 1 + 1 = 9

No. of cubes in the above fig. = 9

Question 2.

Two dice are placed side by side as shown. Can you say what the total would be on the faces opposite to them. (Page No. 274)

i) 5 + 6 ii) 4 + 3

Solution:

i) Sum of the opposite faces = 2 + 1 = 3

ii) Sum of the opposite faces = 3 + 4 = 7

Question 3.

Three cubes each with 2 cm are placed side by side to form a cuboid. Try to make an oblique sketch and say what could be its length, breadth and height. (Page No. 274)

Solution:

Length =2 + 2 + 2 = 6cm

Breadth = 2 cm

Height = 2 cm

Do This

Question 1.

Make clay (or plasticine) models of the following solids and make vertical or horizontal cuts. Draw rough sketches of the cross-sections you obtain. Name them if possible. (Page No. 274)

Solution:

Question 2.

What cross-section do you get when you give a i) vertical cut ii) horizontal cut to the following solids. (Page No. 275)

a) A brick

b) A round apple

c) A die

d) A circular pipe

e) An ice-cream cone

Solution:

Solid | Vertical cut | Horizontal cut |

Brick | Square/rectangle | Rectangle |

A round apple | Circle | Circle |

Die | Square | Square |

Circular pipe | Rectangle | Circle |

ice-cream cone | Triangle | Circle |