Answer:
Step-by-step explanation:
Step one:
given that the sides of the quadrilateral are:
6,8,7, and 9 in dimension.
And the side corresponding to 7 now measures 12
we may agree that the side has increased by 5cm, hence 5 has been added to that side.
Step two:
we can say that the other side will increase as follows
[tex]side_6= 6+5= 11cm\\\\side_8=8+5=13cm\\\\side_9=9+5=14cm\\\\[/tex]