"Which special version of the Pythagorean Theorem can you use to find the

Question

length of any square's diagonal, d, using only the length of its side, s?"

I have no idea what this means, I saw a question like this in another question but didn't quite understand please help!

And please don't rat me out if you somehow find out who I am to my school-
They'll friggin kick me out-
Thanks!

Answer 1

the square's diagonal is the hypotenuse of an isosceles right triangle
... the two perpendicular sides are the same length

s^2 + s^2 = h^2 ... 2 s^2 = h^2 ... s√2 = h

find the diagonal by multiplying the side by √2