In the given fig. the circle touch the lines at X, Y, Z, B, C and D. If PQ = 8 cm, QA = 9 cm and PA = 7 cm, then the length PX, AZ and QY are respectively.
3 cm, 4 cm, 5 cm
Let, AX = AZ = a , QZ = QY = b , PX = PY = c
We know PA = a + c = 7 cm ..........(i) PQ = b + c = 8 cm .......(ii) QA = a + b = 9 cm .........(iii)
(ii) - (iii) → (c + b) - (a + b) = 8 - 9 → c - a = -1 ........(iv)
(iv) + (i) → (c - a) + (a + c) = -1 + 7 → 2 c = 6 ; c = 3 cm
subtituting c in (i) → a + 3 = 7 ; a = 4 cm
subtituting c in (ii) → 3 + b = 8 ; b = 5 cm.
so, PX = c = 3 cm ; AZ = a = 4 cm ; QY = b = 5 cm.