Ayo, kerjakan soal-soal berikut! 1. Hitunglah keliling lingkaran berikut! PR a. C. e. 7 cm 30 cm 21 cm K=… K=… K=.. b. d. f. 10 cm 28 cm 20 cm K=… K=.. K=…​

Penjelasan dengan langkah-langkah:

a. 7 cm

k = 2 × phi × r = 2 × 22/7 × 7 = 44 cm

b. 30 cm

k = 2 × phi × r = 2 × 3,14 × 30 = 188,4 cm

c. 21 cm

k = 2 × phi × r = 2 × 22/7 × 21 = 132 cm

d. 10 cm

k = 2 × phi × r = 2 × 3,14 × 10 = 62,8 cm

e. 28 cm

k = 2 × phi × r = 2 × 22/7 × 28 = 176 cm

f. 20 cm

k = 2 × phi × r = 2 × 3,14 × 20 = 125,6 cm