Chord AB of a circle is produced to a point P, and C is a point on the circle such that PC is a tangent to the circle. If PC = 12 cm, and BP = 10 cm, then the length of AB (in cm) is:

4.4

Let AB be x cm.

AP = AB + PB = x + 10

\( {PC }^{2 } \) = AP x PB

= \( {12 }^{2 } \) = 10 x (x + 10)

= \(\frac{144}{10}\) = x + 10

= x + 10 = 14.4

= x + 14.4 - 10

= x = 4.4

Therefore, The length of chord AB is 4.4 cm.