## MAFS.912.G-CO.3.9: Prove theorems about lines and angles; use theorems about lines and angles to solve problems. Theorems include: vertical angles are congruent; when a transversal crosses parallel lines, alternate interior angles are congruent and corresponding angles are congruent; points on a perpendicular bisector of a line segment are exactly those equidistant from the segment’s endpoints.

There are 42 resources.
Title Description Thumbnail Image Curriculum Topics

## Math Examples Collection: Geometric Proofs

### Overvie

Parallel Lines and Definition of a Triangle

## Math Clip Art Collection: Angles

### Overview

Angles and Applications of Angles and Planes

## Math Definitions Collection: Geometry

3-Dimensional Figures, Definition of an Angle, Exploring Coordinate Systems, Geometric Constructions with Points and Lines, Definition of a Point, Definition of a Triangle, Definition of a Circle, Definition of Transformations, The Distance Formula, Definition of a Polygon, Definition of a Plane, Definition of a Line, Midpoint Formula, Applications of Polygons, Right Triangles, Trig Expressions and Identities, Definition of a Quadrilateral, Applications of Points and Lines, Proportions, Area and Perimeter of Triangles, Area and Perimeter of Quadrilaterals and Pyramids

## Math Definitions Collection: Geometry Theorems and Postulates

### O

Definition of a Triangle, Definition of an Angle, Right Triangles and Definition of a Line

## Definition--Geometry Basics--Perpendicular Bisector

### Definition--Geometry Basics--Perpendicular Bisector This collection of clip art images includes image sequences for key topics in geometry. This includes points, lines, planes, angles, triangles, quadrilaterals, and polygons. Each sequence of images provides an overview of the topic.Note: The download is a PNG file.

Definition of a Line

## Definition--Theorems and Postulates--AAA Theorem

### Definition--Theorems and Postulates--AAA Theorem This is part of a collection of definitions of geometric theorems and postulates.

Definition of a Triangle

## Definition--Theorems and Postulates--AAS Theorem

### Definition--Theorems and Postulates--AAS Theorem This is part of a collection of definitions of geometric theorems and postulates.

Definition of a Triangle

## Definition--Theorems and Postulates--Alternate Interior Angles Theorem

### Definition--Theorems and Postulates--Alternate Interior Angles Theorem This is part of a collection of definitions of geometric theorems and postulates.

Definition of an Angle

## Definition--Theorems and Postulates--ASA Theorem

### Definition--Theorems and Postulates--ASA Theorem This is part of a collection of definitions of geometric theorems and postulates.

Definition of an Angle

## Definition--Theorems and Postulates--Converse of Same-Side Interior Angles Postulate

### Definition--Theorems and Postulates--Converse of Same-Side Interior Angles Postulate This is part of a collection of definitions of geometric theorems and postulates.

Definition of an Angle

## Definition--Theorems and Postulates--Converse of the Alternate Interior Angles Theorem

### Definition--Theorems and Postulates--Converse of the Alternate Interior Angles Theorem This is part of a collection of definitions of geometric theorems and postulates.

Definition of an Angle

## Definition--Theorems and Postulates--Converse of the Corresponding Angles Theorem

### Definition--Theorems and Postulates--Converse of the Corresponding Angles Theorem This is part of a collection of definitions of geometric theorems and postulates.

Definition of an Angle

## Definition--Theorems and Postulates--Corresponding Angles Theorem

### Definition | Theorems and Postulates | Corresponding Angles Theorem This is part of a collection of definitions of geometric theorems and postulates.

Definition of an Angle

## Definition--Theorems and Postulates--Perpendicular Bisector Theorem

### Definition--Theorems and Postulates--Perpendicular Bisector Theorem This is part of a collection of definitions of geometric theorems and postulates.

Definition of a Line

## Definition--Theorems and Postulates--Same-Side Interior Angles Postulate

### Definition--Theorems and Postulates--Same-Side Interior Angles Postulate This is part of a collection of definitions of geometric theorems and postulates.

Definition of a Triangle

## Definition--Theorems and Postulates--SAS Similarity Theorem

### Definition--Theorems and Postulates--SAS Similarity Theorem This is part of a collection of definitions of geometric theorems and postulates.

Definition of a Triangle

## Definition--Theorems and Postulates--SAS Theorem

### Definition--Theorems and Postulates--SAS Theorem This is part of a collection of definitions of geometric theorems and postulates.

Definition of a Triangle

## Definition--Theorems and Postulates--SSS Postulate

### Definition--Theorems and Postulates--SSS Postulate This is part of a collection of definitions of geometric theorems and postulates.

Definition of a Triangle

## Instructional Resource: Tutorial: What Is the Angle Addition Postulate?

### Instructional Resource: Tutorial: What Is the Angle Addition Postulate? In this tutorial, learn what the Angle Addition Postulate is and how to use it to solve problems. —Click on Preview to see the tutorial—

Applications of Angles and Planes

## Math Clip Art--Angle Illustrations--Supplementary Angles--Labeled

### Math Clip Art--Angle Illustrations--Supplementary Angles--Labeled This is part of a collection of clip art images showing different types of angles. Each type of angle measure includes a labeled and unlabeled version.

Angles and Applications of Angles and Planes

## Math Clip Art--Angle Illustrations--Supplementary Angles--Unlabeled

### Math Clip Art--Angle Illustrations--Supplementary Angles--Unlabeled This is part of a collection of clip art images showing different types of angles. Each type of angle measure includes a labeled and unlabeled version.

Angles and Applications of Angles and Planes

## Math Example--Geometric Proofs--Example 1

### Math Example--Geometric Proofs--Example 1 This is part of a collection of math examples that focus on geometric proofs.

Parallel Lines and Definition of a Triangle

## Math Example--Geometric Proofs--Example 10

### Math Example--Geometric Proofs--Example 10 This is part of a collection of math examples that focus on geometric proofs.

Parallel Lines and Definition of a Triangle

## Math Example--Geometric Proofs--Example 11

### Math Example--Geometric Proofs--Example 11 This is part of a collection of math examples that focus on geometric proofs.

Parallel Lines and Definition of a Triangle

## Math Example--Geometric Proofs--Example 12

### Math Example--Geometric Proofs--Example 12 This is part of a collection of math examples that focus on geometric proofs.

Parallel Lines and Definition of a Triangle