Exercise 2.3 - Chapter 2 Measurements 8th Maths Guide Samacheer Kalvi Solutions - SaraNextGen [2024-2025]

Updated By SaraNextGen

On April 24, 2024, 11:35 AM

Ex $2.3$
Question 1.
Fill ini the blanks:
(i) The three dimensions of a cuboid are ___, ____ and ____
Answer:
length, breadth, height
(ii) The meeting point of more than two edges in a polyhedron is called as
Answer:
Vertex
(iii) A cube has faces.
Answer:
six
(iv) The cross section of a solid cylinder is
Answer:
circle
(v) If a net of a 3-D shape has six plane squares, then it is called
Answer:
cube

Question $2 .$
Match the following

Answer:
(i) $-\mathrm{b}$
(ii) $-\mathrm{a}$
(iii) $-d$
(iv) - c

Question 3 .
Which 3 - D shapes do the following nets represents? Draw them.

Answer:
The net represents cube, because it has 6 squares.

Question $4 .$
For each solid, three views are given. Identify for each solid, the corresponding Top, Front and Side (T, F and S) views.

Answer:

Question $5 .$
Verify Euler's formula for the table given below.

Answer:
Euler's formula is given by $\mathrm{F}+\mathrm{V}-\mathrm{E}=2$
(i) $\mathrm{F}=4 ; \mathrm{V}=4 ; \mathrm{E}=6$
$\mathrm{F}+\mathrm{V}-\mathrm{E}=4+4-6=8-6$
$\mathrm{F}+\mathrm{V}-\mathrm{E}=2$
$\therefore$ Euler's formula is satisfied.
(ii) $\mathrm{F}=10 ; \mathrm{V}=6 ; \mathrm{E}=12$
$\mathrm{F}+\mathrm{V}-\mathrm{E}=10+6-12=16-12=4 \neq 2$
$\therefore$ Euler's formula is not satisfied.
(iii) $\mathrm{F}=12 ; \mathrm{V}=20 ; \mathrm{E}=30$
$\mathrm{F}+\mathrm{V}-\mathrm{E}=12+20-30=32-30=2$
$\therefore$ Euler's formula is satisfied.
(iv) $\mathrm{F}=20 ; \mathrm{V}=13 ; \mathrm{E}=30$
$\mathrm{F}+\mathrm{V}-\mathrm{E}=20+13-30=33-30=3 \neq 2$
$\therefore$ Euler's formula is not satisfied.
(v) $\mathrm{F}=32 ; \mathrm{V}=60 ; \mathrm{E}=90$
$\mathrm{F}+\mathrm{V}-\mathrm{E}=32+60-90=92-90=2$
$\therefore$ Euler's formula is satisfied.