I'm ASSUMING this is a 45-45-90 right triangle and that DF is the hypotenuse.
With that said. Angle F = 45 means that angle = 45 and angle E = 90 degrees.
There is only one rule for 45-45-90 right triangles:
hypotenuse = √(2) * leg
Given the hyp = 16
16 = √(2) * leg
divide both sides by √(2)
16/√(2) = leg
Rationalize the denominator
16√(2)/(√(2)*√(2) =
(16√(2)) / 2 =
8√2
