The m∠EDF of the isosceles triangle given ∠EDF and ∠EFD are equal is 51.5°
To locate the angle of the isosceles triangle,
The pair of equal angles are at D and F, as they are both equal yet unknown, we can label them both as x.
The angle at E = 77°
Where ∠EDF = ∠EFD
As angles in a triangle add up to 180°,
i.e Sum of interior angle of triangle = 180°
So, 77° + x + x = 180°
77° + 2x = 180°
2x = 180° - 77°
2x = 103°
x = 103/2
x = 51.2°
Therefore, the ∠EDF of the isosceles triangle given is 51.5°