Perimeter is where you add up all the sides, which is 5+5+4+6+7+9=36cm
so, is a semi-circle, half a circle, recall a circle has a total of 360°, so half of that will be 180°.
the diameter of that circle is 10, so its radius is half that, or 5.
![\bf \textit{arc's length}\\\\ s=\cfrac{\theta \pi r}{180}~~ \begin{cases} r=radius\\ \theta =angle~in\\ \qquad degrees\\[-0.5em] \hrulefill\\ \theta =180\\ r=5 \end{cases}\implies s=\cfrac{(180)(\pi )(5)}{180}\implies s=5\pi \stackrel{\pi =3.14}{\implies s=15.7}](https://tex.z-dn.net/?f=%5Cbf%20%5Ctextit%7Barc%27s%20length%7D%5C%5C%5C%5C%20s%3D%5Ccfrac%7B%5Ctheta%20%5Cpi%20r%7D%7B180%7D~~%20%5Cbegin%7Bcases%7D%20r%3Dradius%5C%5C%20%5Ctheta%20%3Dangle~in%5C%5C%20%5Cqquad%20degrees%5C%5C%5B-0.5em%5D%20%5Chrulefill%5C%5C%20%5Ctheta%20%3D180%5C%5C%20r%3D5%20%5Cend%7Bcases%7D%5Cimplies%20s%3D%5Ccfrac%7B%28180%29%28%5Cpi%20%29%285%29%7D%7B180%7D%5Cimplies%20s%3D5%5Cpi%20%5Cstackrel%7B%5Cpi%20%3D3.14%7D%7B%5Cimplies%20s%3D15.7%7D)
472378 could be 472 amd 178261 as 178 so the best estimate is 660
4cms would be 0.04 meters.
Incomplete question. However, I answered from a general mathematical perspective.
<u>Explanation:</u>
Interestingly, the term <u>strategy</u> has always been synonymous with a thought "plan of action". While written methods often refer to recognized standards of performing operations.
Hence, many prefer to use written methods to perform mathematical operations like multiplications, divisions, etc because they are verified means of solving most mathematical problems.