Question 1169958
y=2x+4 and y=-x+13
{{{graph(300,300,-10,15,-10,20,2x+4,-x+13)}}}

The angle 2x makes with the x-axis is where the tangent of the angle=2 and that is at 63.43 degrees
the angle -x makes with the x-axis is 45 degrees facing to the left but 135 degrees with the positive direction.

That makes the triangle formed by the x-axis and the two lines as 45 degrees, 63.43 degrees, and the third angle is 71.57 degrees.