Respuesta :

Answer: 30

Step-by-step explanation:

The angles of triangles have to add up to 180°

So:

x + x + 70 + x + 20 = 180

Bring like terms together

x + x + x + 70 + 20 = 180

3x + 90 = 180

Subtract 90 from both sides

3x = 90

Divide both sides by 3

x = 30