9514 1404 393
Answer:
21
Explanation:
When secants meet, the product of the length of the pieces from the meeting point to the two circle intersection points is the same for all.
KL·KM = KJ·KC
Assuming the marks inside the circle apply only to the lengths inside the circle:
8(8+x+5) = 7(7+2x+1)
104 +8x = 56 +14x
48 = 6x
8 = x
Then the measure of MK is ...
MK = x+13 = 8+13
MK = 21