Access Point #: MAFS.912.G-CO.4.AP.12eArchived Access Point

Construct perpendicular lines, including the perpendicular bisector of a line segment.

Essential Understandings


  • When given a line segment, use manipulatives (e.g., ruler, compass, string, reflective devices, paper folding, dynamic geometric software, etc.) to bisect the given segment forming perpendicular lines.

    Image of a bisected angle.
  • Place compass point on A and stretch the compass MORE THAN half way to point B, but not beyond B.

  • With this length, swing a large arc that will go BOTH above and below begin mathsize 12px style stack A B with bar on top end style.
  • Without changing the span on the compass, place the compass point on B and swing the arc again. The two arcs that have been created should intersect.

  • With a straightedge, connect the two points of intersection.

  • This new straight line bisects begin mathsize 12px style stack A B with bar on top end style.
  • Label the point where the new line and begin mathsize 12px style stack A B with bar on top end style cross as C.
  • begin mathsize 12px style stack A B with bar on top end style has now been bisected and AC = CB. (It could also be said that the segments are congruent, begin mathsize 12px style stack A C with bar on top space approximately equal to space stack C B with bar on top end style)
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  • Understand the following concepts and vocabulary: perpendicular, bisector, line segment and midpoint.
  • Perpendicular lines are two lines that cross forming 90° angles.
  • A perpendicular bisector is a perpendicular line or a segment that passes through the midpoint of a line.

    Image of a perpendicular bisector.
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General Information
Number: MAFS.912.G-CO.4.AP.12e
Category: Access Points
Date Adopted or Revised: 07/14
Cluster: Make geometric constructions. (Geometry - Supporting 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

This access point is an alternate version of the following benchmark(s).

Related Courses

This access point is part of these courses.
1200400: Foundational Skills in Mathematics 9-12
1206310: Geometry
1206320: Geometry Honors
0101340: Three-Dimensional Studio Art 2
0101350: Three-Dimensional Studio Art 3 Honors
0104340: Drawing 1
0104350: Drawing 2
0104360: Drawing 3 Honors
0104370: Painting 1
0104380: Painting 2
0104390: Painting 3 Honors
0109310: Portfolio Development: Drawing-Honors
0109320: Portfolio Development: Two-Dimensional Design Honors
0109330: Portfolio Development: Three-Dimensional Design Honors
0114800: Florida's Preinternational Baccalaureate Art 1
0114810: Florida's Preinternational Baccalaureate Art 2
7912070: Access Mathematics for Liberal Arts
0101355: Creating Two-Dimensional Art
0101365: Creating Three-Dimensional Art
1206315: Geometry for Credit Recovery
1207300: Liberal Arts Mathematics 1
7912065: Access Geometry
0104335: Drawing 1
7967015: Access Drawing 1
0104412: Figure Drawing 2

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