Đáp án:$\widehat{HBK}=125^{\circ}$
Giải thích các bước giải:
Ta có: $\widehat{AHE}=90^{\circ}$
$\widehat{HAK}=55^{\circ}$
$\widehat{BKA}=90^{\circ}$
⇒$\widehat{HBK}=360^{\circ}-(\widehat{AHE}+\widehat{HAK}+\widehat{BKA})$
=$360-(90+55+90)=360-235=125^{\circ}$