Perimeter of regular octagon is _____ .

The cost of fencing a $15\mathrm{m}\times 7 \mathrm{m}$ rectangular park at $₹45 \mathrm{per} \mathrm{metre}$ is _____.

If the area of a rectangle is $52.4 {\mathrm{m}}^2$, then its possible dimensions are _____.

The area of a square with perimeter $40 \mathrm{cm}$ is _____.

Distance covered in moving $3$ rounds of square park of side $5 \mathrm{m}$ is _____.