Angle Relations in Geometry 📐

In geometry, angle relations are fundamental concepts that describe how angles interact with each other. Here are key types and their proofs:

1. Vertical Angles

When two lines intersect, they form vertical angles (also called opposite angles) that are always equal.

**Proof**: Use the **linear pair postulate** and the fact that angles around a point sum to 360°. 🔗 [Explore more about angle basics](/en/proofs/geometry_basics)

2. Supplementary Angles

Two angles are supplementary if their measures add up to 180°.

**Proof**: Apply the **straight line theorem** and properties of adjacent angles. 🔍 [Check interactive examples](/en/proofs/angle_examples)

3. Complementary Angles

Angles are complementary when their sum is 90°.

**Proof**: Use the **right angle definition** and triangle angle sum properties. 💡 [Learn about triangle angle relations](/en/proofs/triangle_angles)

4. Corresponding Angles

When a transversal crosses two parallel lines, corresponding angles are equal.

**Proof**: Rely on the **parallel postulate** and congruent triangle properties. 📌 [Deep dive into parallel lines proofs](/en/proofs/parallel_lines)

5. Alternate Interior Angles

These angles are formed when a transversal crosses two parallel lines, and they are equal.

**Proof**: Use the **consecutive interior angles theorem** and congruence. 📊 [Download printable worksheets](/en/proofs/angle_worksheets)

For visual learners, interactive diagrams are available to demonstrate these relationships dynamically.