Question

Hitunglah keliling lingkaran jika diketahui
a. r=20 cm
b. r=4,2 cm
c. r=35 cm
d. r=40 cm

Answer 1

Rumus : 2 × phi × r

a. K = 2 × 3,14 × 20 cm
= 125,6 cm

b. K = 2 × 22/7 × 4,2
= 2 × 22 × 0,6
= 26,4 cm

c. K = 2 × 22/7 × 35
= 2 × 22 × 5
= 220 cm

d. K = 2 × 3,14 × 40
= 251,2 cm