To solve for the measure of angle ∠DBC, we can use the information given.
We know that:
- ∠ABC = 155°
- ∠ABD = 60°
Since angles ∠ABC and ∠ABD share a common vertex (B) and form a straight line, we can calculate ∠DBC as follows:
- The total measure of angles around point B is 360°.
- Therefore, to find ∠DBC, we can use the following relationship:
∠DBC = 360° - (∠ABC + ∠ABD)
Substituting the known angles:
∠DBC = 360° - (155° + 60°) ∠DBC = 360° - 215° ∠DBC = 145°
Thus, the measure of ∠DBC is 145°.
However, since none of the responses provided include 145°, we need to consider if the angle could also be expressed relative to a different angle measure using the circle property:
- Conversely, we can find the exterior angle by calculating 360° - 145° = 215°.
Therefore, the measure of ∠DBC is 215°.
The answer is: 215°