Question

Name the definition or state the theorem that justifies the statement about the diagram.

If $\overleftrightarrow{RS}\perp \overleftrightarrow{TV}$, then $\angle 8\cong \angle 7$.

Short answer

The used definition is the definition of congruent adjacent angles.

Step-by-step solution

Step 1. Observe the given statement and figure.

The provided congruent angles are the result of relation between the provided lines.

Step 2. Identify the definition or theorem.

The observation of statement returns the definition of congruent adjacent angles that is the formation of congruent adjacent angles is done when two lines are having a relation that is perpendicular.

Step 3. State whether the definition is true or not.

As the definition of congruent adjacent angles matches with the provided statement so the definition of congruent adjacent angles is the required definition.