Question

The diagonal of a square is $4\sqrt{2}cm$. The diagonal of another square whose area is double that of the first square is :

• A. 8 cm
• B. $8\sqrt{2}cm$
• C. $4\sqrt{2}cm$
• D. 16 cm

Answer 1

The correct option is A 8 cm

Diagonal of a square $\sqrt{2}\times$ side $=\sqrt{2}\times 4\sqrt{2}=4$
$\therefore$ side $=4cm$

Area of this square $4^2=16sqcm$
Area of another square double the area of this square $=32sqcm$
=> Its side $=\sqrt{32}=4\sqrt{2}$
So, length of the diagonal of this second square $=\sqrt{2}\times 4\sqrt{2}=4\times 2=8cm$