Access Point #: MAFS.912.G-CO.3.AP.9a (Archived Access Point)


This document was generated on CPALMS - www.cpalms.org



Measure lengths of line segments and angles to establish the facts about the angles created when parallel lines are cut by a transversal and the points on a perpendicular bisector.

Clarifications:

Essential Understandings

Concrete:

  • Given an angle measure, draw an angle.
  • Use a protractor to show that angles are supplementary (equals 180 degrees).
  • Use a protractor to show that angles are equal.
  • Recognize that the angle measure of a straight line is 180 degrees.
  • Identify vertical angles, adjacent angles, and supplementary angles, given a set of parallel lines cut by a transversal.
  • Identify congruent angles, given a set of parallel lines cut by a transversal.
  • Identify alternate interior angles, given a set of parallel lines cut by a transversal.
  • Construct parallel lines crossed by a transversal.
  • Measure line segments on a line.
  • Given a line segment, use paper folding to determine the perpendicular bisector.
Representation:
  • Match or identify angle measurements.
  • Understand the following concepts and vocabulary: acute, obtuse, right, straight line, vertical angles, parallel lines, alternate interior angles, perpendicular bisector, equal distance, transversal.
  • Describe parallel lines by telling about or showing lines and angles.
  • Label adjacent angle measurements on a diagram of parallel lines cut by a transversal given one of the angles, using subtraction to find the missing angle.
  • Identify points on a perpendicular bisector of a line segment are equidistant from the segment’s endpoints.
  • Identify angle relationships based on position given a diagram of parallel lines cut by a transversal.
  • Use appropriate tools as needed.

Number: MAFS.912.G-CO.3.AP.9a Category: Access Points
Date Adopted or Revised: 07/14 Cluster: Prove geometric theorems. (Geometry - Major Cluster)

Clusters should not be sorted from Major to Supporting and then taught in that order. To do so would strip the coherence of the mathematical ideas and miss the opportunity to enhance the major work of the grade with the supporting clusters.

Related Standards

Name Description
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.



Related Courses

Name Description
1200400: Foundational Skills in Mathematics 9-12
1206310: Geometry
1206320: Geometry Honors
1206315: Geometry for Credit Recovery
7912065: Access Geometry