Question

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

If $m\angle 5=90$, then $\overleftrightarrow{RS}\perp \overleftrightarrow{TV}$.

Short answer

The used definition is the definition of perpendicular lines.

Step-by-step solution

Step 1. Observe the given statement and figure.

The provided relation between lines is the result of provided measurement of ∠5.

Step 2. Identify the definition or theorem.

The observation of the statement returns the definition of perpendicular lines that is the relation between two lines is perpendicular when the measurement of angles formed by those lines is equal to 90°.

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

As the definition of the perpendicular line matches with the provided statement so the definition of perpendicular lines is the required definition.