Answer:
Let there be a square ABCD with diagonal AC=12 root 2 cm
Since angles of a square are all 90 degrees
pythagoras theoream
AB^2+BC^2=AC^2
Since all sides of square are equal
2AB^2=(12 root 2)^2
2AB ^2=144*2
AB^2=144
AB= root 144=12 cm
area of square = s^2 =12^2 = 144cm^2
hope it helps
Step-by-step explanation: