Answer: 5
Explanation:
To start off, the angles of a triangle add up to 180.
Therefore, you would find he answer by adding all the angles together and making it equal to 180.
13x+17x+6x=180
When you solve the equation, you will get X=5.
To check your work:
13 times 5=65
17 times 5=85
6 times 5=30
65+85+30=180