Answer:
10
Explanation:
First, we know that the angles of a triangle add up to 180 degrees. We can then sum up our angles as 90 (since it's a right triangle, represented by the square in the bottom left angle) +27+6x+3=180
90+27+6x+3=180
Add up left side
120+6x=180
Subtract 120 from both sides
6x=60
Divide both sides by 6
x=10