Using the diagram from the previous context, determine the value of x and angles A1, B2, A3, B4.

Here are the solutions for the requested angles, using the diagram from the previous context.

First, let's determine the value of $x$.
From the diagram, lines $EF \parallel GH$. The line $AB$ is a transversal.
Angles $\hat{A}_3$ and $\hat{B}_2$ are alternate interior angles.
Therefore, $\hat{A}_3 = \hat{B}_2$.

$$2x = x + 10^\circ$$ $$2x - x = 10^\circ$$ $$x = 10^\circ$$

Now we can calculate the angles:

3.3.3 Determine $\hat{A}_1$

Step 1: Identify the relationship between $\hat