tolong bantu jawab ya no 20-23 menggunakan caranya

21.k=2πr=176
2 x 22/7 x r=176
r=176 x 7/44
r=28
l= πr²=22/7 x 28 x 28 =2464cm²

20. d
21. K = 176 cm, L = ?
      K = [tex]2 \pi r [/tex]
     176 = 2 × 22/7 × r
     176 = 44/7 × r
     r = 176 × 7/44
     r = 4 × 7
     r = 28 cm

    L = [tex] \pi r^{2} [/tex]
    L = 22/7 × 28 × 28
    L = 2464 cm^2 (a)

Semoga membantu ^^