Answer:
15 degrees
Step-by-step explanation:
3x+3x+90=180 (all angles in a triangle add to 180 degrees)
3x+3x=6x so 6x+90=180 degrees
To isolate 6x we -90 from 180 therefore 6x=90 degrees
To get x on its own, we then must divide 90 by 6 which is 15 hence why...
x=15 degrees
