berapa luas lingkaran jika diketahui kelilingya 88 cm ?

K = pi × d
88 cm = 22/7 × d
d = 7/22 × 88 cm
= 28 cm

L = pi × r²
= 22/7 × 14 ×14
= 22 × 2 × 14
= 616 cm²

K = 2 x phi x r
88 = 2 x 22/7 x r
88 = 44/7 x r
r = 88 x 7/44
r = 2 x 7
r = 14 cm

Luas lingkaran = phie x r²
                          = 22/7 x 14 x 14
                          = 616 cm²

semoga membantu.....