Tolong yaaaa kak.....

No. 3
keliling lingkaran = phi x d
22/7 × 28 × 3/4 = 66
66 + 14 + 14 = 94 cm
Luas lingkaran = phi x r kuadrat
22/7 × 14 × 14 × 3/4
462 cm

No. 4
Luas lingkaran = phi x r kuadrat
1256 = 3,14 × r kuadrat
r kuadrat = 1256 : 3,14
r kuadrat = 400
r = 20 cm

keliling lingkaran = phi x d
3,14 x 40
125,6 cm

No. 5
Juring
135
----- × 3,14 × 10 × 10 = 117,5 cm
360

No. 6
lintasan = keliling x putaran
lintasan = (22/7 × 42) × 500
lintasan = 66.000 cm = 66 km

No.7
ADB = 50°
AOB = 2× 50°
100°
Maka BOC = 80°