hitunglah keliling lingkaran jika diketahui a.jari-jari 21cm b.diameter 218 c.diameter15 cm

a. jari-jari r = 21 cm
keliling = 2 π r = 2 x 22/7 x 21 = 132 cm
b. diameter d = 218 cm
karena d = 2 r, maka
keliling = π d = 22/7 x 218 = 685,1 cm
c. diameter d = 15cm, maka
keliling = π d = 22/7 x 15 = 47,1 cm

Diket :
a) r=21 cm
b) d=218cm
c) d=15cm
tanya :
kel ling. = π R^2
Jawab :
a) =[tex] {2} \times \frac{22}{7} \times {21} [/tex]
=132cm
b) =[tex] {2} \times \frac{22}{7} \times \frac{218}{2} [/tex]
=685,1cm
c) =[tex] {2} \times {3,14} \times \frac{15}{2} [/tex]
=47,1cm