Answer:
| EF | = 1.97
Explanation:
If Angle FDE is 26 degrees, then Angle DFE is 90 - 26 (degrees), or 64 degrees.
Since cos 64 degrees = 0.438, the length of EF is 4.5 cos 64 degrees, or
| EF | = 4.5(0.438) = 1.971.
| EF | = 1.97 (to two decimal places)