Geometric Angle Relationships and Formulas
This page presents a comprehensive overview of fundamental geometric concepts related to angles in various shapes. It covers essential formulas and rules for understanding angle relationships in triangles, quadrilaterals, and polygons.
Highlight The document provides a quick reference guide for key angle facts and formulas in geometry.
Triangle Angles
The page begins by discussing angles in triangles
Definition Angles in a triangle add up to 180°.
This is a fundamental principle in geometry. The document also mentions specific types of triangles
Vocabulary In an isosceles triangle, the base angles are equal.
Example In an equilateral triangle, all angles are equal and measure 60°.
Quadrilateral Angles
Moving on to quadrilaterals, the document states
Definition Angles in a quadrilateral add up to 360°.
This is another crucial concept in geometry, applicable to all four-sided shapes.
Angles on Lines and Around Points
The page covers several important angle relationships
- Angles on a straight line add up to 180°.
- Angles around a point add up to 360°.
- Vertically opposite angles are equal.
- Alternate angles are equal Z−rule.
- Corresponding angles are equal F−rule.
- Supplementary angles add up to 180° C−rule.
These relationships are fundamental in understanding angle properties in various geometric configurations.
Polygon Angles
The document concludes with formulas for angles in polygons
Definition The sum of exterior angles of a polygon is always 360°.
Highlight Sum of interior angles of a polygon formula n−2 × 180°, where n is the number of sides.
Vocabulary For a regular polygon, the exterior angle formula is 360° ÷ n, where n is the number of sides.
Definition The interior angle of a regular polygon formula is (n−2)×180° ÷ n.
Lastly, it notes that for any polygon, the sum of an interior angle and an exterior angle at the same vertex is always 180°.
This comprehensive guide serves as an excellent resource for students studying geometry, providing essential formulas and concepts for understanding angle relationships in various shapes.