Straight angles measure \( 180^{\circ} \) When lines intersect to form right angles, they are classified lines.

When lines intersect to form right angles, they are classified as **perpendicular** lines. ### Explanation: - **Straight Angle:** A straight angle measures \( 180^{\circ} \). It represents a straight line where two rays extend in exactly opposite directions. - **Perpendicular Lines:** When two lines intersect and form right angles (each measuring \( 90^{\circ} \)), they are called **perpendicular lines**. This means the lines meet or cross each other at a precise right angle. #### Visual Representation: ``` | | -----+----- | | ``` In the diagram above, the intersecting lines form four right angles, demonstrating that they are perpendicular to each other. ### Key Points: - **Straight Angle:** Measures \( 180^{\circ} \). - **Right Angle:** Measures \( 90^{\circ} \). - **Perpendicular Lines:** Two lines that intersect at a right angle. If you have any more questions or need further clarification on geometric concepts, feel free to ask!