Answer:
30
Step-by-step explanation:
all angles add up to 180*, 180-90=90, 90=3x, 30=x
x = 30
One side is 90 so the other two sides have to add up to 90 too because a triangles' angles have to add up to 180.
So, we can write that 2x + x = 90
Then we can solve for x:
2x + x = 90
3x = 90
