I also tried some constructions but couldn't solve it.
2026-03-26 17:11:55.1774545115
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Angle chasing in a square
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Draw diagonal AC and construct $\angle CAH=20$
Now $\triangle ADE$ is congruent to $\triangle BAH$ (A.A.S.)
Then AE = AH since $\angle EAH=40, \angle AHE=AEH=70$.
Now look at quadrilateral AFHE $\angle AFB=70$ and $\angle AEH=70$ then quadrilateral AFHE is cyclic therefore $\angle FAH=\angle FEH=5$
Then you get $x+5=70$
$x=65$



Rotate around $A$ for $90^{\circ}$. Then $D$ goes to $B$ and $E$ to new point $E'$.
Then $F,B$ and $E'$ are colinear and triangle $AEF$ is congruent to triangle $AFE'$ (sas) and thus $$x = \angle AE'F = 180 -70-45 = 65$$