Question

use the figure to complete each part.
(a) write two other names for $angle 1$.
$\boldsymbol{square}$ and $\boldsymbol{square}$
(b) name the sides of $angle 2$.
$\boldsymbol{square}$ and $\boldsymbol{square}$
(c) name the vertex of $angle dbc$.
$\boldsymbol{square}$

Explanation:

(a) An angle can be named by its vertex (when no other angles share that vertex) or by three points with the vertex in the middle. ∠1 has vertex B, so it can be ∠B, and also ∠ABC (or ∠CBA, with vertex B between the two sides' points).
(b) The sides of an angle are the two rays that form it. ∠2 is formed by rays starting at B going to C and to D.
(c) The vertex of an angle is the common endpoint of its two sides. For ∠DBC, the common endpoint is B.

Answer:

(a) $\angle ABC$ and $\angle B$
(b) $\overrightarrow{BC}$ and $\overrightarrow{BD}$
(c) $B$