NCERT Solutions for class 8 Maths chapter 4 Practical geometry

Exercise 4.1  Exercise 4.2  Exercise 4.3  Exercise 4.4  Exercise 4.5

Exercise 4.5

Question 1

Draw the following:

The square READ with RE = 5.1 cm

Sol :

All the sides of a square are of the same measure and also all the interior angles of a square are of 90º measure. Therefore, the given square READ can be drawn as follows.

(Step-1)A rough sketch of this square READ can be drawn as follows.

(Step-2) Draw a line segment RE of 5.1 cm and an angle of 90º at point R and E.

(Step-3) As vertex A and D are 5.1 cm away from vertex E and R respectively, cut line segments EA and RD, each of 5.1 cm from these rays.

(Step-4) Join D to A.

READ is the required square.

 

Question 2

Draw the following:

A rhombus whose diagonals are 5.2 cm and 6.4 cm long.

Sol :

In a rhombus, diagonals bisect each other at 90º. Therefore, the given rhombus ABCD can be drawn as follows.

(Step-1)A rough sketch of this rhombus ABCD is as follows.

(Step-2) Draw a line segment AC of 5.2 cm and draw its perpendicular bisector. Let it intersect the line segment AC at point O.

(Step-3) Draw arcs of on both sides of this perpendicular bisector. Let the arcs intersect the perpendicular bisector at point B and D.

(Step-4) Join points B and D with points A and C.

ABCD is the required rhombus.

 

Question 3

Draw the following:

A rectangle with adjacent sides of length 5 cm and 4 cm.

Sol :

Opposite sides of a rectangle have their lengths of same measure and also, all the interior angles of a rectangle are of 90º measure. The given rectangle ABCD may be drawn as follows.

(Step-1)A rough sketch of this rectangle ABCD can be drawn as follows.

(Step-2) Draw a line segment AB of 5 cm and an angle of 90º at point A and B.

(Step-3) As vertex C and D are 4 cm away from vertex B and A respectively, cut line segments AD and BC, each of 4 cm, from these rays.

(Step-4) Join D to C.

ABCD is the required rectangle.

 

Question 4

Draw the following:

A parallelogram OKAY where OK = 5.5 cm and KA = 4.2 cm.

Sol :

Opposite sides of a parallelogram are equal and parallel to each other. The given parallelogram OKAY can be drawn as follows.

(Step-1)A rough sketch of this parallelogram OKAY is drawn as follows.

 

(Step-2) Draw a line segment OK of 5.5 cm and a ray at point K at a convenient angle.

(Step-3) Draw a ray at point O parallel to the ray at K. As the vertices, A and Y, are 4.2 cm away from the vertices K and O respectively, cut line segments KA and OY, each of 4.2 cm, from these rays.

(Step-4) Join Y to A.

OKAY is the required parallelogram.

 

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