Tolong dijawab pakai cara. soalnya bsk dikumpul

k = 2 × π × r       L = π × r²

1. dik : r = 21 cm
    k = 2× 22/7 × 21 = 132 cm
    L = 22/7 × 21 ×21 = 1386 cm²

2. dik r = 20cm
 k= 2 × 3,14 × 20 = 125,6 cm
  l = 3,14 × 20×20 = 1256 cm²

3. dik r = 36cm
    k = 2× 3,14 ×36 = 226,08 cm
   l= 3,14 × 36 ×36 = 4069, 44 cm²

4. dik r = 84 cm
   k = 2 x 22/7 x 84 = 528 cm
  l = 22/7 x 84 x 84 = 22176 cm²

maaf klau slah