The area of a square is 441 sq cm. What is the length of its side?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 21 cm
The area of a square is side × side, so the side is the square root of the area. Splitting 441 into prime factors gives the root quickly.
\(441=3\times3\times7\times7=(3\times7)^2\)
\(\sqrt{441}=3\times7=21\)
Side \(=21\) cm
