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On January 25, 2024, 11:35 AM

Exercise 15.1 - Chapter 15 Visualising Solid Shapes class 7 ncert solutions Maths - SaraNextGen [2024]


Question 1:

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

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1828/Chapter%2015_html_2793bdb.jpg

Answer:

(i)The given net can be folded as follows.

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1828/Chapter%2015_html_59186674.jpg

When the faces that are in sky blue colour and in pink colour are folded to make a cube, they will be overlapping each other.

(ii) The given net can be folded as follows.

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1828/Chapter%2015_html_47109d38.jpg

A cube can thus be formed in the above way.

(iii) The given net can be folded as follows.

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1828/Chapter%2015_html_m5406bdff.jpg

A cube can thus be formed in the above way.

(iv) The given net can be folded as follows.

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1828/Chapter%2015_html_1d624172.jpg

A cube can thus be formed in the above way.

(v) The given net can be folded as follows.

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1828/Chapter%2015_html_m538ffe83.jpg

When the faces that are in blue colour and in red colour are folded to make a cube, they will be overlapping each other.

(vi) The given net can be folded as follows.

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1828/Chapter%2015_html_m69cb43ce.jpg

A cube can thus be formed in the above way.

Question 2:

Dice are cubes with dots on each face. Opposite faces of a die always have a total of seven dots on them.

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1831/Chapter%2015_html_m142efd4.jpg

Here are two nets to make dice (cubes); the numbers inserted in each square indicate the number of dots in that box.

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1831/Chapter%2015_html_m20c91126.jpg

Insert suitable numbers in the blanks, remembering that the number on the opposite faces should total to 7.

Answer:

(i) The numbers can be inserted as follows so as to make the given net into a net of a dice.

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1831/Chapter%2015_html_669ef171.jpg

It can be observed that the sum of the opposite faces is 7.

(ii)The numbers can be inserted as follows so as to make the given net into a net of a dice.

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1831/Chapter%2015_html_m1a7a6d06.jpg

It can be observed that the sum of the opposite faces is 7.

Question 3:

Can this be a net for a die?

Explain you Answer

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1833/Chapter%2015_html_4c2ef37e.jpg

Answer:

The given net can be folded as follows.

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1833/Chapter%2015_html_51fb3b36.jpg

It can be observed that the opposite faces of the dice so formed have 2 and 5, 1 and 4, 3 and 6 on them. The sum of the numbers on the opposite faces comes to 7, 5, 9 respectively. However, in case of a dice, the sum of the numbers on the opposite faces should be 7. Hence, this net is not of a dice.

Question 4:

Here is an incomplete net for making a cube. Complete it in at least two different ways. Remember that a cube has six faces. How many are there in the net here? (Give two separate diagrams. If you like, you may use a squared sheet for easy manipulation.)

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1835/Chapter%2015_html_4a415a2f.jpg

Answer:

There are 3 faces in the given net. The given net can be completed as follows.

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1835/Chapter%2015_html_1e22c41c.jpg

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1835/Chapter%2015_html_m4fb3eec7.jpg

Question 5:

Match the nets with appropriate solids:

(a)

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1842/Chapter%2015_html_ma690592.jpg

(i)

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1842/Chapter%2015_html_m6ecfd73f.jpg

(b)

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1842/Chapter%2015_html_m193881e0.jpg

(ii)

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1842/Chapter%2015_html_mb16346d.jpg

(c)

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1842/Chapter%2015_html_1b521eac.jpg

(iii)

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1842/Chapter%2015_html_3f18dbcd.jpg

(d)

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1842/Chapter%2015_html_m3e7e4507.jpg

(iv)

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1842/Chapter%2015_html_m29788d96.jpg

Consider net (i). It can be folded as follows.Answer:

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1842/Chapter%2015_html_67a84691.jpg

It is a net of a pyramid. Hence, (d) is the correct matching option.

Consider net (ii). It can be folded as follows.

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1842/Chapter%2015_html_m6e170a28.jpg

It is a net of a cube. Hence, (a) is the correct matching option.

Consider net (iii). It can be folded as follows.

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1842/Chapter%2015_html_m2ae779e9.jpg

It is a net of a cylinder. Hence, (b) is the correct matching option.

Consider net (iv). It can be folded as follows.

https://img-nm.mnimgs.com/img/study_content/curr/1/7/3/45/1842/Chapter%2015_html_583935a2.jpg

It is a net of a cone. Hence, (c) is the correct matching option.

Also Read : Exercise-15.2-Chapter-15-Visualising-Solid-Shapes-class-7-ncert-solutions-Maths

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