Jari jari= diameter=21cm. keliling=​

Jawaban:

d = 21 cm

jari-jari (r) = 1/2.d = 1/2 x 21 cm = 10,5 cm

keliling = πd = 22/7 x 21 = 66 cm

luas = πr² = 22/7 x (10,5)² = 22/7 x 110,5 = 346,5 cm²

Penjelasan dengan langkah-langkah:

dik, d = 21 cm

dit, r, K, dan L ?

penyelesaian :

r = 1½d

r = 1½ x 21

r = 10,5 cm

K = nd

K = 22/7 x 21

K = 22/1 x 3

K = 66 cm

L = πr²

L = 22/7 x 10,5 × 10,5

L = 2425,5/7

L = 346,5 cm²