Jawab plis

Jawaban:

8. luas lingkaran=phi x r²

154 =22/7 x r²

49 =r²

7 =r

diameter=2 x r

=2 x 7

=14 cm

9. luas lingkaran a : luas lingkaran b

(phi x r x r) : (phi x r x r)

(22/7 x 7 x 7) : (22/7 x 21 x 21)

1 : 9

10. keliling lingkaran=2 x phi x r

44=2 x 22/7 x r

7=r

luas lingkaran=phi x r x r

=22/7 x 7 x 7

=154 cm²

Penjelasan dengan langkah-langkah:

8. luas = 154 cm²

L = πr²

154 = 22/7 × r²

r² = 154 × 7/22

r² = 1078/22

= 49

diameter = 2×r = 2 × 7 = 14

9. r1 = 7cm dan r2 = 21 cm

L1 = π×r² = 22/7 × 7² = 22/7 × 49 = 1078/7 = 154 cm²

L2 = π×r² = 22/7 × 21² = 22/7 × 441 = 9702/7 = 1386 cm²

L1 : L2 = 154 : 1386

L1 : L2 = 22 : 198

L1 : L2 = 1 : 9

10. K = 44 cm

ditanya L = …?

jawab:

K = 2πr

L = π×r²

L = 22/7 × 7²

L = 22/7 × 49

L = 1078/7

= 154 cm²