Answer:
See below.
Explanation:
I'm sure the question is asking to solve for ∠BDC, but we'll solve for all of the angles.
We should note that we have a Given Exterior Angle.
What is an Exterior Angle?
An Exterior Angle is an angle that is formed by extended lines.
An exterior angle is equal to the combined sum of the two nonadjacent, and interior angles.
Using what we learned, ∠BCD and ∠CDB will equal ∠DBE°.
Let's turn this problem into an equation.
60° + ∠BDC = 120°
Subtract 60 from both sides.
∠BDC = 60°.
We can also identify that ∠CBD is a linear pair with ∠DBE.
What is a Linear Pair?
A Linear Pair is 2 adjacent angles that add up to 180°. Linear Pairs are straight lines with one line intersecting in between.
Meaning that ∠CBD + ∠DBE = 180°.
∠CBD + 120° = 180°.
∠CBD = 60°.
We can identify that this triangle is an Equilateral Triangle. An Equilateral Triangles is a triangle that has all congruent sides and angles.
Our final answers are;
∠BDC = 60°.
∠CBD = 60°.