The diagonal of a square is 12 cm long. find its area and length of one side.
Let side of square be a cm, diagonal =12 cm
By Pythagoras Theorem,
a2+a2=(12)2
⇒2a2=144
⇒a2=72
∴ Area of square =a2 =72 cm2
a2=72
⇒a=√72=8.49 cm
Hence, area of the square is 72 cm2 and the length of the one side is 8.49 cm.