Answer:
4.
[tex]a = 2\pi rh + 2(\pi {r}^{2} )[/tex]
[tex]a = 2\pi(4)(12) + 2\pi( {4}^{2} ) = 128\pi = 402.124 {cm}^{2} [/tex]
5.
[tex]a = \pi rl = \pi(5)(7) = 35\pi = 109.96 {cm}^{2} [/tex]
6.
[tex]a = 4\pi {r}^{2} = 4\pi(2) ^{2} = 16\pi = 50.27dm ^{2} [/tex]
