Answer:
C
Step-by-step explanation:
Given 2 secants from an external point to the circle, then
The product of the external part and the whole of one secant is equal to the product of the external part and the whole of the other secant , that is
ML × KM = MN × MR, substitute values
7 × KM = 6(6 + 8)
7 KM = 6 × 14 = 84 ( divide both sides by 7 )
KM = 12 → C
