Question

If a square has a side of length $4cm$, what is the length of the diagonal?

• A. $8cm$
• B. $4cm$
• C. $4\sqrt{2}cm$
• D. $8\sqrt{2}cm$

Answer 1

The correct option is C

$4\sqrt{2}cm$

The diagonal of a square divides the square into two right-angled triangles. Now, here in the square ABCD with side length $4cm$, using Pythagoras theorem, we have

$AC=\sqrt{A{B}^2+B{C}^2}=\sqrt{4^2+4^2}=\sqrt{32}=4\sqrt{2}cm$