Question

A square with a side of 18 is decreased to a side of 15. By how much is the diagonal decreased?

Answer 1

Find the diagonal of the big square:

18^2 + 18^2 = c^2
sqrt(18^2 + 18^2) = c

Then find the diagonal of the small square:

15^2 + 15^2 = C^2
sqrt( 15^2 + 15^2) = C

Then subtract to find the difference... try that.