NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas Ex 4.5

Ncert solutions for class 6 maths chapter 4 basic geometrical ideas ex 4.5 ncert solutions for class 6 maths chapter 4 exercise 4.5 ncert solutions class 6 maths chapter 4 exercise 4.5 ncert class 6 maths chapter 4 exercise 4.5 class 6 maths chapter 4.

NCERT Solutions for Class 6 Maths Chapter 4 Basic Geometrical Ideas Ex 4.5

Question 1.
Draw a rough sketch of a quadrilateral PQRS. Draw its diagonals. Name them. Is the meeting point of the diagonal in the interior or exterior of the quadrilateral?
Solution :

The meeting point O of the diagonals PR and QS of the quadrilateral PQRS is in the interior of the quadrilateral PQRS.

Question 2.
Draw a rough sketch of a quadrilateral KLMN. State :
(a) two pairs of opposite sides.
(b) two pairs of opposite angles.
(c) two pairs of adjacent sides.
(d) two pairs of adjacent angles.
Solution :
(a) KL¯, NM¯ and KN¯, ML¯
(b) ∠K, ∠M and ∠N, ∠L
(c) KL¯ , KN¯ and NM¯, ML¯ or KL¯ , LM¯ and NM¯, ML¯

(d) ∠K, ∠L, and ∠M. ∠N or ∠K. ∠L and ∠L, ∠M etc.

Question 3.
Investigate:
Use strips and fasteners to make a triangle and a quadrilateral. Try to push inward at any one vertex of the triangle. Do the same to the quadrilateral. Is the triangle distorted? Is the quadrilateral distorted? Is the triangle rigid? Why is it that structures like electric towers make use of triangular shapes and not quadrilaterals?
Solution :
On pushing inward at any one vertex of the triangle, the triangle is not distorted, However, the quadrilateral is distorted. Hence, a triangle is a rigid figure. This is why structures like electric towers make use of triangular shapes and not quadrilaterals.

Question 1

Identify simple closed curves

Solution

A figure is a simple closed curve if:

• It is closed
• It does not intersect itself

Answer:

$\text{Closed figures without crossing are simple closed curves}$

Question 2

Which figures are polygons?

Solution

Figures that:

• Have straight sides
• Are closed

are polygons.

Answer:

$\text{Triangle, Square, Rectangle are polygons}$

Question 3

Which is NOT a polygon?

Solution

• Circle (curved boundary)
• Open figures

are NOT polygons.

Answer:

$\text{Circle is not a polygon}$

Question 4

Identify types of figures

Solution

• Closed curve → Simple closed curve
• Straight-sided closed figure → Polygon

Answer:

$\text{Simple closed curves and polygons}$