Answer:
B
Explanation:
The diagonal will become the hypotenuse of a right triangle, with the legs being 24 and 7.
Since it is a right triangle, we can use Pythagorean theorem
a^2+b^2=c^2
We know the legs: a and b, are 24 and 7, so we can substitute them in
24^2+7^2=c^2
Solve the exponents
576+49=c^2
Add
625=c^2
Take the square root of both sides
=
c=25
So, the diagonal will be 25 cm, or choice B