Question 1164781
<br>
The other tutor didn't read the given information correctly.<br>
The 6cm is the length of the diagonal of each small square -- not the side length.<br>
So the side length of each square is {{{6/sqrt(2)=3*sqrt(2)}}} cm.<br>
Then the diagonal AC is the hypotenuse of a right triangle with legs {{{18*sqrt(2)}}} cm and {{{24*sqrt(2)}}} cm.<br>