Question

What is the perimeter of a square whose sides are 7cm?

Answer 1

Hint: We have to know about the perimeter and the area of a square to solve this question. We know that a square has all four sides as equal. So, to find the perimeter of a square with a given side, the basic approach would be to put the value of the given side in the formula for the perimeter of the square, which is given by, 4a, where a is the side.

Complete step-by-step solution:
We have been asked in the question to find the perimeter of a square with the given side of 7cm. We know the formula for the perimeter of a square is given as 4a, where a is the side of the square. If we consider a square with side a as given below,

Now, we know that perimeter = sum of all the sides.
Since a square has all the four sides equal, we can say that its,
Perimeter = a + a + a + a
So, the perimeter = 4a
Now in our question, we have been given the side as 7cm or a = 7cm. So, we have,
Perimeter = 4a
$\Rightarrow $ Perimeter = 4 $\times $ 7cm
$\therefore $ Perimeter = 28cm
Hence the perimeter of a square with side 7cm is 28cm.

Note: The most common mistake in this question would be to apply the wrong formula for calculating the perimeter of the square or not writing the proper units. In case you have doubts about the correct formula, you can simply add all the sides to get the answer. Do not use the formula for area and end up with the wrong answer.