Hitunglah luas dan keliling lingkaran ​

Jawaban:

a. Lingkaran 1

Luas = phi x r x r

= 3,14 x 10,5 x 10,5

= 346,185 cm2

Keliling = phi x d

= 3.14 x 21

= 65.94 cm

b. Lingkaran 2

Luas = phi x r x r

= 22/7 x 21 x 21

= 1386 cm2

Keliling = 2 x phi x r

= 2 x 22/7 x 21

= 924/7

= 132 cm

c. Lingkaran 3

Luas = phi x r x r

= 3,14 x 30 x 30

= 2826 cm2

Keliling = 2 x phi x r

= 2 x 3,14 x 30

= 188,4 cm