Tentukan luas dan keliling lingkaran jika diameter nya 40 cm π=3,14

Pembahasan :
Luas lingkaran
[tex] = \pi \times {r}^{2} \\ = 3.14 \times 20 \times 20 \\ = 1256 \: \: {cm}^{2} [/tex]

Keliling lingkaran
[tex] = \pi \times d \\ = 3.14 \times 40 \\ = 125.6 \: \: cm[/tex]

Good Luck ^^

luas = phi x r x r = 3.14 x 400=1256
keliling = 2 x phi x r =2 x 3.14 x 20
=125.6