Since ∠ABD is given as 112°, ∠ABC and ∠CBD form a linear pair with ∠ABD.
A linear pair of angles adds up to 180°.
Therefore, ∠ABC + ∠CBD = 180°.
Substituting the given value, we can set up the equation:
112° + ∠CBD = 180°.
To find ∠CBD, we need to isolate it on one side of the equation.
Subtracting 112° from both sides of the equation, we get:
∠CBD = 180° - 112°.
Simplifying the right side of the equation, we have:
∠CBD = 68°.
Now that we have found the measure of ∠CBD, we can substitute it back into the equation:
∠ABC + 68° = 180°.
To find ∠ABC, we need to isolate it on one side of the equation.
Subtracting 68° from both sides of the equation, we get:
∠ABC = 180° - 68°.
Simplifying the right side of the equation, we have:
∠ABC = 112°.
Therefore, the measure of ∠ABC is 112° and the measure of ∠CBD is 68°.