Tolong di jawab no4 a,b beserta cara dan rumusnya yahh (MATEMATIKA KLS8)

luas (a)
[tex] \frac{ {60}^{o} }{ {360}^{o} } \times \frac{22}{7} \times 42 \times 42 = \\ \frac{1}{6} \times \frac{22}{7} \times 42 \times 42 = \\ 924 {cm}^{2} [/tex]