Answer: 5.25
Explanation:
In the picture there is a smaller triangle inside a bigger triangle. You have to find the size it grows by dividing a side of the bigger triangle to the same side of the smaller triangle.
16.8/6.4 = 2.625
Then you find x by multiplying the adjacent side by the size it grows.
2*2.626 = x
2*2.626 = 5.25