Answer:
As ΔABC is an isosceles triangle:
⇒ BA = BC
(the dashes on the line segments indicate they are of equal measure)
⇒ ∠BAC = ∠BCA = 55°
⇒ ∠BCA = ∠BAD = 55°
Angles on a straight line sum to 180°
⇒ ∠ADE + ∠EDC = 180°
⇒ 98° + ∠EDC = 180°
⇒ ∠EDC = 82°
As BE intersects AC, the vertically opposite angles are equal:
⇒ ∠BDC = ∠ADE = 98°
⇒ ∠ADB = ∠EDC = 82°
Interior angles in a triangle sum to 180°
⇒ ∠BAD + ∠ADB + ∠ABD = 180°
⇒ 55° + 82° + ∠ABD= 180°
⇒ ∠ABD = 180° - 55° - 82°
⇒ ∠ABD = 43°
