Answer:
10.67 degree.
Explanation:
Note:
The angle between two lines can be found using their direction cosines. The formula is:

where:
- a and b are the direction cosines of the two lines
is the angle between the two lines- ||a|| and ||b|| are the magnitudes of a and b
In this case, the direction cosines of the two lines are proportional to 1, 2, 3 and 3, 4, 5.
So, we can write the direction cosines as follows:
a = (1, 2, 3)
b = (3, 4, 5)
The magnitudes of a and b are:


Now, we can find the angle between the two lines using the formula above:

The angle theta can be found using the arc cos function or inverse cos function.
Therefore, the angle between the two lines is 10.67 degree.