tolong jawab ya, makasih...

1. L = [tex] \pi [/tex] . r^2
   =314/100 . 20.20
   = 1256 cm^2
2. L = [tex] \pi [/tex] . r^2. 1/4
       =314/100 . 100 . 1/4
       = 78,5 cm^2

No 1
luas lingkaran=3,14x20x20

=1256