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On March 11, 2024, 11:35 AM

Exercise 4.2 - Chapter 4 Practical Geometry class 8 ncert solutions Maths - SaraNextGen [2024]


Question 1:

Construct the following quadrilaterals.

(i) Quadrilateral LIFT

LI = 4 cm

IF = 3 cm

TL = 2.5 cm

LF = 4.5 cm

IT = 4 cm

(ii) Quadrilateral GOLD

OL = 7.5 cm

GL = 6 cm

GD = 6 cm

LD = 5 cm

OD = 10 cm

(iii) Rhombus BEND

BN = 5.6 cm

DE = 6.5 cm

Answer:

(i) A rough sketch of this quadrilateral can be drawn as follows.

https://img-nm.mnimgs.com/img/study_content/curr/1/8/5/67/3270/Chapter%204_html_m66a1d709.jpg

(1) Δ ITL can be constructed by using the given measurements as follows.

https://img-nm.mnimgs.com/img/study_content/curr/1/8/5/67/3270/Chapter%204_html_m72e1b7b2.jpg

(2) Vertex F is 4.5 cm away from vertex L and 3 cm away from vertex I. Therefore, while taking L and I as centres, draw arcs of 4.5 cm radius and 3 cm radius respectively, which will be intersecting each other at point F.

https://img-nm.mnimgs.com/img/study_content/curr/1/8/5/67/3270/Chapter%204_html_m71feea7b.jpg

(3) Join F to T and F to I.

https://img-nm.mnimgs.com/img/study_content/curr/1/8/5/67/3270/Chapter%204_html_m68d83f5a.jpg

LIFT is the required quadrilateral.

(ii)A rough sketch of this quadrilateral can be drawn as follows.

https://img-nm.mnimgs.com/img/study_content/curr/1/8/5/67/3270/Chapter%204_html_18b68a75.jpg

(1) Δ GDL can be constructed by using the given measurements as follows.

https://img-nm.mnimgs.com/img/study_content/curr/1/8/5/67/3270/Chapter%204_html_m4ce8ef15.jpg

(2) Vertex O is 10 cm away from vertex D and 7.5 cm away from vertex L. Therefore, while taking D and L as centres, draw arcs of 10 cm radius and 7.5 cm radius respectively. These will intersect each other at point O.

https://img-nm.mnimgs.com/img/study_content/curr/1/8/5/67/3270/Chapter%204_html_m413161d2.jpg

(3) Join O to G and L.

https://img-nm.mnimgs.com/img/study_content/curr/1/8/5/67/3270/Chapter%204_html_299c517f.jpg

GOLD is the required quadrilateral.

(iii) We know that the diagonals of a rhombus always bisect each other at 90º. Let us assume that these are intersecting each other at point O in this rhombus.

Hence, EO = OD = 3.25 cm

A rough sketch of this rhombus can be drawn as follows.

https://img-nm.mnimgs.com/img/study_content/curr/1/8/5/67/3270/Chapter%204_html_35d5bda2.jpg

(1) Draw a line segment BN of 5.6 cm and also draw its perpendicular bisector. Let it intersect the line segment BN at point O.

https://img-nm.mnimgs.com/img/study_content/curr/1/8/5/67/3270/Chapter%204_html_m3f0c38d6.jpg

(2) Taking O as centre, draw arcs of 3.25 cm radius to intersect the perpendicular bisector at point D and E.

https://img-nm.mnimgs.com/img/study_content/curr/1/8/5/67/3270/Chapter%204_html_317284d5.jpg

(3) Join points D and E to points B and N.

https://img-nm.mnimgs.com/img/study_content/curr/1/8/5/67/3270/Chapter%204_html_m2d97d1a0.jpg

BEND is the required quadrilateral.

Also Read : Exercise-4.3-Chapter-4-Practical-Geometry-class-8-ncert-solutions-Maths

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