Answer:
a) [tex]p = 88\,cm[/tex], b) [tex]p = 24\,cm[/tex], c) [tex]p \approx 25.424\,m[/tex], d) [tex]p \approx 39.368\,cm[/tex]
Step-by-step explanation:
a) The perimeter is the sum of the three sides of the internal square and the remaining sides of the external rectangle, that is:
[tex]p = 3\times 8\,cm + 2\times 4\,cm +2\times 20\,cm + 16\,cm[/tex]
[tex]p = 88\,cm[/tex]
b) The perimeter is the sum of the two sides of the internal triangle and the remaining sides of the external rectangle, that is:
[tex]p = 2\times 4\,cm + 2\times 6\,cm + 4\,cm[/tex]
[tex]p = 24\,cm[/tex]
c) The perimeter is the sum of the two sides of the circular section and the three sides of the lower rectangle, that is:
[tex]p = \frac{\pi}{2}\times 6\,cm + 8\,cm + 6\,cm + 2\,cm[/tex]
[tex]p \approx 25.424\,m[/tex]
d) The perimeter is the sum of the external sides of the triangle and rectangle, that is:
[tex]p = 10\,cm + 12\,cm + 12\,cm + 12\,cm - \sqrt{(12\,cm)^{2}-(10\,cm)^{2}}[/tex]
[tex]p \approx 39.368\,cm[/tex]
