MCQ 11 Mark
The side of a square is $10\ cm$. How many times will the new perimeter become if the side of the square is doubled?
- ✓$2$ times
- B$4$ times
- C$6$ times
- D$8$ times
Answer
View full question & answer→Correct option: A.
$2$ times
Given, side of a square $= 10\ cm$
We know that, perimeter of a square $= 4 \times $ Side $= 4 \times 10$
$= 40\ cm$
$\therefore$ Perimeter of old square $= 40\ cm$
Now, according to the question, side of the square is doubled.
New side$ = 2 \times 10 = 20\ cm$
Again, perimeter of new square = 4 \times Side
$= 4 \times 20 = 80\ cm$
$\therefore$ New perimeter
$= 2 \times $ (Old perimeter)
$= 2 \times 40 = 80\ cm$
Hence, the new perimeter is $2$ times of the old perimeter.
We know that, perimeter of a square $= 4 \times $ Side $= 4 \times 10$
$= 40\ cm$
$\therefore$ Perimeter of old square $= 40\ cm$
Now, according to the question, side of the square is doubled.
New side$ = 2 \times 10 = 20\ cm$
Again, perimeter of new square = 4 \times Side
$= 4 \times 20 = 80\ cm$
$\therefore$ New perimeter
$= 2 \times $ (Old perimeter)
$= 2 \times 40 = 80\ cm$
Hence, the new perimeter is $2$ times of the old perimeter.









