Question

4 squares each of side 1 cm are cut out from a square of side 4 cm. The length of the boundary of the resulting shape is ___.

• A. 9 cm
• B. 12 cm
• C. 16 cm
• D. 20 cm

Answer 1

The correct option is C 16 cm


When four squares of side 1 cm each are cut out from a square of side 4 cm, we obtain the shape as in the above image.

The length of the boundary of the resulting shape is
$2\text{cm}+2\text{cm}+2\text{cm}+2\text{cm}+1\text{cm}+1\text{cm}+1\text{cm}+1\text{cm}+1\text{cm}+1\text{cm}+1\text{cm}+1\text{cm}=16\text{cm}.$

Note that the perimeter of the larger square too is $16\text{cm}.$

$(16\text{cm}=4\times a=4\times (4\text{cm}\left)\right)$