Penjelasan dengan langkah-langkah:

Jawab :

Diketahui :

Panjang busur BC = 22 cm

∠COD = 30°

∠BOC = 90° - 30° = 60°

∠OAB = 180° - 90° = 90°

Ditanyakan :

A] Panjang busur CD

B] Keliling lingkaran

C] Luas lingkaran

D] Luas juring AOB

Penyelesaian :

A] Panjang busur CD/Panjang busur BC = ∠COD/∠BOC

Panjang busur CD/22 cm = 30°/60°

Panjang busur CD = 22 x 30 / 60

Panjang busur CD = 11 cm

B] Panjang busur BC = ∠BOC / 360° x Keliling lingkaran

22 cm = 60° / 360° x Keliling lingkaran

Keliling lingkaran = 22 cm x 360/60

Keliling lingkaran = 132 cm

C] K = 2 x π x r

132 = 2 x 22/7 x r

132 = 44/7 x r

r = 132 x 7/44

r = 21 cm

Luas lingkaran

= π x r²

= 22/7 x 21 cm x 21 cm

= 1.386 cm²

D] Luas juring AOB

= ∠AOB / 360° x Luas lingkaran

= 90° / 360° x 1.386 cm²

= 1/4 x 1.386 cm²

= 346,5 cm²

• TOLONG LIKE NYA YAA!.