Answer:
[tex]a=\sqrt{170}[/tex]
Step-by-step explanation:
Diagonal of a Square
Given a square of length side a, the length of the diagonal is
[tex]D=\sqrt{2}a[/tex]
The diagonal of a rectangle of sides x and y is
[tex]D=\sqrt{x^2+y^2}[/tex]
The sides have lengths 12 cm and 14 cm, the diagonal is
[tex]D=\sqrt{12^2+14^2}[/tex]
[tex]D=\sqrt{340}[/tex]
Since this value is the same of the diagonal of certain square, we can say
[tex]\sqrt{2}a=\sqrt{340}[/tex]
Dividing by [tex]\sqrt{2}[/tex]
[tex]\boxed{a=\sqrt{170}}[/tex]