Question

find Diagonal of a Square of Side 12cm.

Answer 1

Pythagoras theorem
AB^2+BC^2=AC^2
144+144=AC^2
AC=16.97cm

Answer 2

(hypotenuse)^2 = (side)^2 + (side)^2 
=(√12)^2+(√12)^2
=144+144
=288
(hypotenuse)^2=√288

d=16.97