NCERT Solutions For Class 6 Maths, Chapter 4, Basic Geometrical Ideas, Exercise 4.5 is all about sides in quadrilateral. Quadrilateral is a four-sided polygon. Exercise 4.5 class 6 maths chapter 4 involves total two questions to study.
NCERT Solutions For Class 6 Maths, Chapter 4, Basic Geometrical Ideas, Exercise 4.5
Q.1. Draw a rough sketch of a quadrilateral PQRS. Draw its diagonals. Name them. Is the meeting point of the diagonals in the interior or exterior of the quadrilateral?
Ans: PR and QS are the diagonals. They meet at point O which is in the interior of the quadrilateral PQRS.
Q.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.
Ans:
(a) Two pairs of opposite sides: KL and MN, KN and LM.
(b) Two pairs of opposite angles : ∠N and ∠L, ∠K and ∠M.
(c) Two pairs of adjacent sides : KL and KN, KL and LM.
(d) Two pairs of adjacent angles : ∠K, ∠L and ∠M, ∠N.
Q.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?
Ans: On moving the vertex of triangle , whole triangle moves, but the shape remains same. So, the triangle is rigid.
But in quadrilateral, on moving vertex, the shape gets distorted.
That is why, structures like electric towers make use of triangular shape so that they could not be distorted and they could be rigid.