di ketahui segitiga abc siku siku di a, panjang ab=9, bc=15, pnjng jari jari lingkrannya adlh

r = (9x12)/(9+12+15) = 108/36 = 3 cm

AC = √15^2 - 9^2
= √225 - 81
= √144 = 12 cm
Kell.segitiga = 9+ 8 + 15 = 32
s = 1/2×keliling = 1/2×32 = 16
L = √16(16-9)(16-15)(16-12)
= √16×7×1×4 = √448
= 21,16

jari2 lingkaran dalam = L/s
= 21,16/16 = 1,3225 cm

jari2 lingkaran luar = ABC/4L
= (9×15×12)/4×21,16
= 1620/84,64
= 19,14 cm