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
