Answer:
The correct answer you’re looking for is 60º
Explanation:
To find out the missing angle pair you need to find out what exactly you’re looking for.
We already know that angle measure BED is 90º and combined with angle measure FED they add up to a total of 120º.
Since I chose to do supplementary angles (Angles that are right next to each other and add up to a total of 180º), because of the only numbers given we have to subtract the total number from the numbers given.
In other words 180º - 120º = 60º.
I hope this was helpful!