Kak tolong dijawab Plis cara

Kak tolong dijawab
Plis cara

Kak tolong dijawab
Plis cara

$l = (pi : times : {r}^{2} ) div 2 \ ( frac{22}{7} times 42 times 42) div 2 \ ( frac{22}{7} times1764) div 2 \ ( frac{38808}{7} ) div 2 \ 5544 {cm}^{2} div 2 = 2772 {cm}^{2}$