To solve the problem, we can use the angle sum of triangle,where the addition of all triangles would be equal to 180°.
In this case, 90° is already given, hence we can use the rest angles with unknown to set up equaiton:
90° + 2x + 3x = 180°
2x + 3x = 180°- 90°
5x = 90°
x = 90°/5
x = 18°
Therefore, x= 18°.
Hope it helps!
