hitunglah keliling dan luas lingkaran jila diketahui hal sebagai berikut a.jari=21cm b.jari=30cm c.-----=49cm d.diameter=12cm e.-------------=35cm f.-----------

keliling
a. 22/7 x 21 x 2 = 154 cm
b. 3,14 x 30 x 2 = 188,4 cm
c. 22/7 x 49 x 2 = 308 cm
d. 3,14 x 12 = 37,68 cm
e. 22/7 x 35 = 110 cm
f. 3,14 x 40 = 125,6 cm

luas
a. 1386 cm kubik
b. 2826 cm kubik
c. 7546 cm kubik
d. 113,04 cm kubik
e. 961, 625 cm kubik
f. 1256 cm kubik


maaf kalau salah

1. k=2πr = 2×22/7×21 =2×22×3 = 132
l = πrr = 22/7 ×21×21 = 22×21×3= 1.386
2.k= 2πr = 2×3,14×30= 188,4
l = πrr = 3,14×30×30=2.826
3.k= 2πr = 2×22/7×49=308
l= πrr = 22/7×49×49 = 7.546
4. k=2πr = 2×3.14×6 =37,68
l = πrr= 3.14× 6×6 = 113,04
5. k= 2πr = 2×3.14×17,5=109,9
l= πrr = 3.14×17,5×17,5=961,625
6.k = 2πr =2×3.14×20=125,6
l= πrr = 3.14× 20×20=1256

semoga membantu :)