To find the length of the yellow segment, we have to use Pythagorean's Theorem. But first, we have to find the length of the black line at the bottom.
Where a = 4ft and b = 9ft.
So, the length of the black segment is 9.8 feet.
Now, we find the yellow line length
Where a = 4 and b = 6.
Therefore, the length of the yellow line is 7.2 feet.