9514 1404 393
Answer:
39 units
Explanation:
The angle markings tell you this is an equilateral triangle, so all sides are the same length.
10x -11 = 2x +29
8x = 40
x = 5
Then the side length is ...
2x +29 = 2·5 +29 = 39
The length of side KL is 39 units.