Answer:
∠ BDE = 85°
Step-by-step explanation:
The exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.
∠ ABC is an exterior angle of the triangle, then
∠ C + ∠ BDC = 155
60 + ∠ BDC = 155 ( subtract 60 from both sides )
∠ BDC = 95°
∠ BDE and ∠ BDC are adjacent angles and are supplementary, thus
∠ BDE = 180° - 95° = 85°
