Iniii gimaaana yaa??​

Penjelasan dengan langkah-langkah:

diketahui:

db = 21cm => rb = 21/2 cm

dk = 7cm => rk = 7/2 cm

ditanya:

keliling arsir =?

luas arsir =?

jawab:

K = ½.Kb + ½.Kk + 7+7

= ½.(22/7).(21) + ½.(22/7).(7) + 14

= ½.(66) + ½.(22) +14

= 33+11+14

= 58 cm

L = ½.(22/7).(21/2)² – ½.(22/7).(7/2)²

= ½.(346,5) – ½.(38,5)

= 173,25 – 19,25

= 154 cm²

Penjelasan dengan langkah-langkah:

Keliling

• KB

= 22/7 × 21

= 66

• KK

= 22/7 × 7

= 22

K = 1/2 × KB + 1/2 × KK + (7 + 7)

K = 1/2 × 66 + 1/2 × 22 + 14

K = 33 + 11 + 14

K = 44 + 14

K = 58 cm

Luas

L = 1/2 × (22/7 × 21/2 × 21/2) – 1/2 × (22/7 × 7/2 × 7/2)

L = 1/2 × 346,5 – 1/2 × 18,5

L = 173,25 – 19,25

L = 154 cm²