Juring lingkaran AOB mempunyai panjang busur 16 cm dan luas juringnya 32 cm. Tentukan sudut tetta (AOB)

Panjang busur AOB = 16cm
Misal sudut AOB besarnya x° (=teta)
Panjang busur AOB :
x°/360 × keliling lingkaran =
x°/360 × 2πr = 16
2πrx°/360 = 16 ==> πrx° = 8×360

Luas juring AOB 32 cm^2
x°/360 × πr^2 = 32 ==> x°πr^2 = 32 × 360

x°πr^2 dibagi πrx° = 32×360 dibagi 8×360
(x°πr^2)/(πrx°) = (32×360)/(8×360)
r = 32/8
==> r = 4

πrx° = 8×360 ==> 22/7 × 4 × x° = 8 × 360
x° = (8×360×7)/(22×4)
x° = (360×7)/11
x° = 229°
Jadi, teta = x° = 229°