Question

What is the length of the wooden strip required to frame a photograph of length and breadth 32 cm and 21 cm respectively?

Answer 1

Hint: We solve this question by using the formula for the perimeter for the rectangular frame. This is given by $P=2\left( l+b \right),$ where l is the length of the rectangular frame and b is the breadth of the rectangular frame. Finding the perimeter gives us the length of the wood required to frame the given photograph.

Complete step by step solution:
In order to solve this question, let us first draw the dimensions of the photograph. It is of length 32 cm and breadth 21 cm as shown in the figure below.

We are basically required to calculate the perimeter of this rectangular frame in order to find out the length of the wood needed to frame this photograph. Finding the perimeter of the frame is the same as finding the perimeter of the photograph. Perimeter formula is given by,
$\Rightarrow P=2\left( l+b \right)$
Here, l represents the length which is 32 cm in this case and b represents the breadth which is 21 cm here. Substituting these values in the perimeter formula,
$\Rightarrow P=2\left( 32+21 \right)$
Adding the terms in the brackets,
$\Rightarrow P=2\left( 53 \right)$
Multiplying the two terms,
$\Rightarrow P=106cm$

Hence, the length of the wooden strip required to frame a photograph of length and breadth 32 cm and 21 cm respectively is 106 cm.

Note:
We need to know the basic formula for the perimeter of a rectangle in order to solve this sum. We can also solve this sum by just adding the lengths of the outer boundary of the photograph in order to obtain the length of the wooden strip required to frame the photograph.