tolong pakai cara ya... nomor 4 dan 5

4a. dik
r1= 3 m. r2= 2m
dit. luas yg di arsir

jawab
L1= πr²
=3.14×3²
=3.14×9
=28,26 m²
L2=πr²
=3,14×2²
=3,14×4
=12.56m²
L arsir = L1 - L2
= 28,26 - 12,56
=15,70m²
4b. dik
D=6. r=½D=3 t=7. D= a
dit. luas yg diarsir
jawab:
L1=πr²/2
=3,14×3²/2
=3,14×9/2
=14,13m²
L2=a×t/2
=6×7/2
=21m²
L arsir= L1+L2
= 14,13 + 21
= 35,13m²
4c. dik
p=15cm. l=12cm. l=D. r1=½D=6cm. r2= r3
r2=¼D=3cm
dit. luas yg diarsir
jawab:

L1=πr²/2
=3,14×6²/2
=3,14×36/2
=56,52cm²
L2=πr²/2
=3,14×3²/2
=14,13cm²
L3=L2
=14,13cm²
L4= p×l
= 15×12
= 180cm²
L. arsir= L1-(L2+L3)+L4
= 56,52 +(14,13+14,13)+180
= 208,26cm²
4d. dik
r=a=t=7m
dit. luas yg diarsir
jawab

L1=¼πr²
=¼×22/7×7²
=38,5m²
L2=½a×t
=½ 7×7
=24,5
L. arsir = L1 -L2
= 38,5 -24,5
= 14m²
5. dik
L = 616m²
dit. r=? k=?
Jawab
L =πr²
616=22/7r²
r² =616/22/7
=616×7/22
=196
r =√196
=14 m
k =2πr
=2×22/7×14
=88 m