Explanation:
Referring to diagram, we see two isosceles triangles whose vertex angles are complementary (add up to 90 degrees).
Given the base angle of one is 71, we deduce that the other base angles is also 71. Hence the vertex angle is 180-71-71 = 38.
Since the vertex angles are complementary, we deduce that the angle is 52 degrees.
For the second isosceles triangle, the base angles are (180-52)/2 = 64 degrees.
Since 64 degrees and angle 2 are supplementary,
angle 2 measures 180-64 = 116 degrees.
We're given angle2 = 7x+6, so
x= (116-6)/7 = 110/7
= 17.14 degrees (to the hundredth degree).