Question

Two rectangle pieces of paper strips, each of length $30cm$ and width $3cm$, are pasted at right angles to make the shape of a cross. Find the perimeter of the cross.

Answer 1

Hint: For answering this question we will first find the perimeter of each rectangular piece of the paper strip and then find the total perimeter of the 2 rectangular pieces of the paper strip by using the formula $2\left( l+b \right)$. After that, we will subtract the overlapped section perimeter while making the shape of a cross.

Complete step-by-step solution
Now considering from the question we have 2 rectangle pieces of paper strips each of length $30cm$ and width $3cm$, are pasted at right angles to make the shape of a cross.

So here we can say that the perimeter of each rectangle will be $2\left( l+b \right)=2\left( 30+3 \right)$ .
By simplifying we have two rectangular strips each of perimeter $66cm$.
The total perimeter of the two rectangular strips is $132cm$.
As the two rectangle pieces of paper strips are pasted at right angles to make the shape of a cross. So we will have $4\left( 3 \right)=12cm$ overlapped.
So the total perimeter of the cross will be $132-12=120cm$.
Hence, we can conclude that the two rectangle pieces of paper strips, each of length $30cm$ and width $3cm$, are pasted at right angles to make the shape of a cross.
The perimeter of the cross is $120cm$.

Note: While answering this question we need to be sure with the calculations and the perimeter of the section overlapped. If we forget to subtract the perimeter of the section overlapped while making a cross from the perimeter of the 2 rectangle pieces of the paper strip we will have $132cm$ which is a wrong answer.