Question

use the set of angles shown below to answer the question.
lines 1 and 2 are parallel.
which pair of angles are adjacent angles?
○ ∠a and ∠b
○ ∠c and ∠f
○ ∠d and ∠f
○ ∠b and ∠e

Explanation:

Step1: Recall adjacent angles definition

Adjacent angles share a common side and vertex, and don't overlap.

Step2: Analyze each option

• Option 1: $\angle a$ and $\angle b$ share a common side (the transversal $t$) and vertex (intersection of $t$ and $L_1$), so they are adjacent.
• Option 2: $\angle c$ and $\angle f$: No common side/vertex, not adjacent.
• Option 3: $\angle d$ and $\angle f$: No common side/vertex, not adjacent.
• Option 4: $\angle b$ and $\angle e$: No common side/vertex, not adjacent.

Answer:

$\boldsymbol{\angle a}$ and $\boldsymbol{\angle b}$ (or the option corresponding to $\angle a$ and $\angle b$ in the multiple - choice, e.g., if it's the first option, then "A. $\angle a$ and $\angle b$")