diketahui jari-jari lingkaran O adalah 3 cm dan panjang tali busur AB = 4 cm. Nilai tan α =

r = 3
AB = 4 = pj tali busur

pj tali busur = α°/360° * kell lingkaran

AB = α°/360° * 2πr

4 = α°/360° * 2 * 3,14 * 3

4 = α°/360° * 18,84

4/18,84 = α°/360°

0,2123 = α°/360°

0,2123 * 360° = α°

76,428° = α°

tan α° = 1,6644