Every triangle adds up to 180 degrees and 90 degrees+ 30 degrees is 120 degrees, 180 degrees - 120 degrees would be 60 degrees so the angle of EDF would be 60 degrees

write this in a 7th grade way

In a triangle, all the angles add up to 180 degrees. We know that angle EDF is 90 degrees and angle DFE is 30 degrees. So, if we add these angles together, we get 120 degrees. To find the measure of angle EDF, we subtract 120 degrees from 180 degrees, which equals 60 degrees. Therefore, the angle of EDF is 60 degrees.