Question

dbc is exactly ______ degrees.

Explanation:

Step1: Recall the property of a straight angle

A straight angle measures \(180^{\circ}\). In the figure, \(\angle ABD+\angle DBC = 180^{\circ}\) (since \(A\), \(B\), and \(C\) are collinear).

Step2: Solve for \(\angle DBC\)

Given \(\angle ABD = 120^{\circ}\), we use the equation \(\angle DBC=180^{\circ}-\angle ABD\).
Substitute \(\angle ABD = 120^{\circ}\) into the equation: \(\angle DBC=180 - 120\).

Answer:

\(60\)