We have to calculate the perimeter of this composite figure.
This perimeter will be composed by different segments:
0. One length of the rectangle (21 ft)
,
1. One width of the rectangle (14 ft)
,
2. Another lwngth of the rectangle (21 ft), and
,
3. A semicircle (yet to be calculated).
We can calculate the length of the semicircle as half the perimeter of a circle. The diameter in this case is the width of the rectangle (14 ft).
Then, we can write:
![\begin{gathered} P_(sc)=(1)/(2)(\pi D) \\ P_(sc)\approx(1)/(2)(3.14\cdot14) \\ P_(sc)\approx21.98 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/g1zyl14myeu6lyyu5paz7rqserpm0em7to.png)
Then, we can now calculate the perimeter as the sum of the lengths of the segments we have listed:
![P=21+14+21+21.98=77.98](https://img.qammunity.org/2023/formulas/mathematics/college/hpczs74lc6acbrgmbv2wmet80iiwh5tpvn.png)
Answer: 77.98 ft of fence are required.