Respuesta :

Answer:

30°

Step-by-step explanation:

We know that the angles in triangles always add up to 180°. There is also a right angle in this triangle, which is 90°.

Using this policy, we can assume that:

(3x - 30) + x + 90 = 180

First, we need to combine like terms. We can combine the 3x and the x, and the -30 and the 90.

4x + 60 = 180

Subtract 60 from both sides.

4x = 120

Divide by 4 on both sides.

x = 30