Question

Take four congruent card-board OR paper copies of any quadrilateral ABCD, with angles
as shown [Fig 3.5 (i)]. Arrange the copies as shown in the figure, where angles
∠1, ∠2, ∠3, ∠4 meet at a point [Fig 3.5 (ii)].
Fig 3.4
What can you say about the sum of the angles ∠1, ∠2, ∠3 and ∠4?
[Note: We denote the angles by ∠1, ∠2, ∠3, etc., and their respective measures
by m∠1, m∠2, m∠3, etc.]
The sum of the measures of the four angles of a quadrilateral is___________.
You may arrive at this result in several other ways also

Answer 1

Take four congruent card-board OR paper copies of any quadrilateral ABCD, with angles

as shown [Fig 3.5 (i)]. Arrange the copies as shown in the figure, where angles

∠1, ∠2, ∠3, ∠4 meet at a point [Fig 3.5 (ii)].

Fig 3.4

What can you say about the sum of the angles ∠1, ∠2, ∠3 and ∠4?

[Note: We denote the angles by ∠1, ∠2, ∠3, etc., and their respective measures

by m∠1, m∠2, m∠3, etc.]

The sum of the measures of the four angles of a quadrilateral is___________.

You may arrive at this result in several other ways also