8th Maths 4.3

Chapter 4

Practical Geometry

NCERT Class 8th Solution of Exercise 4.1

NCERT Class 8th Solution of Exercise 4.2

NCERT Class 8th Solution of Exercise 4.4

NCERT Class 8th Solution of Exercise 4.5

EXERCISE 4.3

Q1. Construct the following quadrilaterals.

i) Quadrilateral MORE
MO=6cm
OR=4.5 cm
ZM=60°
ZO=105°
ZR=105°

ii) Quadrilateral PLAN
PL=4 cm
LA=6.5 cm
ZP=90°
ZA=110°
ZN = 85°

iii) Parallelogram HEAR
HE=5cm
EA=6cm
ZR=85°

(iv) Rectangle OKAY
OK = 7 cm
KA=5 cm

`text{Solution:}`

i) `text{Quadrilateral MORE}`
`text{MO=6cm}`
`text{OR=4.5 cm}`
`text{ZM=60°}`
`text{ZO=105°}`
`text{ZR=105°}`

`text{Rough sketch of a quadrilateral MORE}`

`text{Fair sketch of a quadrilateral MORE}`

`text{Step of construction}`

1) `text{Draw OR = 4.5cm.}`

2) `text{Draw two angles of 105° each at O and R}``text{ with the help of a protector.}`

3) `text{Cut OM=6 cm at center O.}`

4) `text{Draw an angle of 60° at M to intersect the}``text{ angle through R at E.}`

5) `text{We get quadrilateral MORE.}`  

ii) `text{Quadrilateral PLAN}`
`text{PL=4 cm}`
`text{LA=6.5 cm}`
`text{ZP=90°}`
`text{ZA=110°}`
`text{ZN = 85°}`

`text{Rough sketch of a quadrilateral PLAN}`

`text{Fair sketch of a quadrilateral PLAN}`

`text{Step of construction}`

1) `text{Draw LA = 6.5cm.}`

2) `text{Draw two angles of 75° at L and  110° at A}``text{ with the help of a protector.}`

`[{360°-(110°+90°+85°)=75°}]`

3) `text{Cut LP=4 cm at center L.}`

4) `text{Draw an angle of 90° at P to intersect the}``text{ angle through A at N.}`

5) `text{We get quadrilateral PLAN.}`  

iii) `text{Parallelogram HEAR}`
`text{HE=5cm}`
`text{EA=6cm}`
`text{ZR=85°}`

`text{Rough sketch of a parallelogram HEAR}`

`text{Fair sketch of a parallelogram HEAR}`

`text{Step of construction}`

`[text{Opposite sides of a parallelogram are equal.}]`

1) `text{Draw HE=5 cm.}`

2) `text{Draw an angle of 85° at E and cut EA=6 cm.}`

3) `text{Draw an arc with the center A and a radius}``text{ 5 cm.}`

5) `text{Draw another arc with a center H of radius}``text{ 6 cm to meet the previous arc at R.}`

6) `text{Join HR, and AR}`

7) `text{We get parallelogram HEAR.}`

iv) `text{Rectangle OKAY}`
`text{OK = 7 cm}`
`text{KA=5 cm}`

`text{Rough sketch of a rectangle OKAY}`

`text{Fair sketch of a rectangle OKAY}`

`text{Step of construction}`

`[text{Each angle of a rectangle is 90° and opposite}``text{ sides are equal.}]`

1) `text{Draw OK=7 cm.}`

2) `text{Draw an angle of 90 at K and cut KA=5 cm.}`

3) `text{Draw an arc with center C of radius 5 cm.}`

4) `text{Draw another arc with a center A of radius}``text{ 7 cm to meet the previous arc at Y.}`

5) `text{Join AY and OY.}`

6) `text{We get rectangle OKAY.}`