Answer:
x=10ft
Explanation:
Hey,
Since, the total height is 26, you add up the individual heights listed on the sides because they have to add up to 26.
So,
x+x+6=26 (From here it is basic algebra where you solve for x)
2x+6=26 (add the two x variables together)
2x=26-6 (subtract the 6)
2x=20 (divide by 2)
x=10 ft
The answer makes sense too because the line segments are larger than the segment 6 which was given.