## Reflection: Continuous Assessment Bisect Angles - Section 5: Construction: Bisect Angles

As I circulated the classroom, I listened for students’ reasoning as they tried to come up with a method for bisecting angles.  An idea came up to connect the two points on each side of the angle with a segment and to perpendicularly bisect that segment.  I decided to write up an Angle Bisector "Math Hospital" to provoke students’ talk around why making the initial arc on the angle is important (to locate two points equidistant from the vertex) and how this construction is essentially the same as the construction for a perpendicular bisector.

Continuous Assessment: Surfacing Misconceptions

# Bisect Angles

Unit 5: Constructions
Lesson 4 of 11

## Big Idea: Students explain the WHY behind each step of the construction to build deeper understanding of the concept of angle.

Print Lesson
Standards:
Subject(s):
Math, Geometry, modeling, Constructions, compass and straightedge
80 minutes

### Jessica Uy

##### Similar Lessons

###### Human Conics: Circles and Ellipses
12th Grade Math » Conic Sections
Big Idea: Students collaborate with partners to become a human conic section and draw circles and ellipses using sidewalk chalk.
Favorites(1)
Resources(23)
Phoenix, AZ
Environment: Urban

###### Verifying Properties of Constructions
Geometry » Triangles and Congruence
Big Idea: Students use interactive geometry software to confirm their predictions about straight-edge and compass constructions. It's all done with triangles!
Favorites(1)
Resources(19)
Ault, CO
Environment: Rural

###### Line It Up!
Geometry » Line-sanity!
Big Idea: In this student-centered lesson, students work together to construct parallel and perpendicular lines while also writing equations for these lines.
Favorites(5)
Resources(39)
Saratoga Springs, NY
Environment: Suburban