No 4 dan 15 tolong jawab, pake cara

[tex]15. \frac{160}{360} \times \pi \times {r}^{2} = 32 \\ {r}^{2} = \frac{32 \times 7 \times 9}{4 \times 22} = \frac{504}{22}[/tex]
POR = 360 - (90 + 160) = 360 - 250 = 110
[tex] \frac{110}{360} \times \pi \times {r}^{2} = \frac{11}{36} \times \frac{22}{7} \times \frac{504}{22} = 22[/tex]