Lesson Plan
EngageNY

Characterize Points on a Perpendicular Bisector

For Students 9th - 10th Standards
Learn transformations through constructions! Pupils use perpendicular bisectors to understand the movement of a reflection and rotation. They discover that the perpendicular bisector(s) determine the line of reflection and the...
Lesson Plan
Curated OER

Cabri Jr. Perpendicular Bisector of a Chord

For Teachers 9th - 12th Standards
Your learners will construct the perpendicular bisector of a chord. They use Cabri Jr. to construct a circle and a perpendicular bisector of a chord. They then measure lengths of the chords and perpendicular bisectors. Learners use...
Lesson Plan
Curated OER

Perpendicular Bisector Theorem

For Teachers 9th - 12th Standards
High schoolers construct perpendicular bisectors using Cabri Jr. on their graphing calculator. They then construct conditional statements about perpendicular bisectors along with their converse, inverse, and contrapositive.
Interactive
CK-12 Foundation

Bisectors of Line Segments and Angles: Cut a Line

For Students 9th - 12th
Geometric constructions build relationships —by simply manipulating simple tools. An interactive lesson presents a completed construction of a segment bisector and has learners analyze the important aspects. Ultimately, they should be...
Lesson Plan
Curated OER

IGD: Perpendicular Bisector

For Teachers 9th - 12th
High schoolers draw perpendicular bisectors.  In this perpendicular bisectors lesson, students identify the perpendicular bisector in a polygon.  They use web tools to create and measure perpendicular bisectors.  High...
Lesson Plan
Curated OER

Constructing Perpendicular Bisectors

For Teachers 10th
Tenth graders investigate parallel lines and the angles formed when cut by a transversal. In this geometry lesson, 10th graders construct perpendicular lines and discuss midpoint, segments and perpendicular bisectors. They relate...
Lesson Plan
Curated OER

Perpendicular Bisector of a Line Segment

For Teachers 9th - 12th Standards
High Schoolers investigate the perpendicular bisector of a line segment. They use Cabri Jr. to construct the perpendicular bisector of a segment. The dynamics capabilities of Cabri Jr. allow your learners to observe the lengths of the...
Lesson Plan
EngageNY

Circles, Chords, Diameters, and Their Relationships

For Teachers 9th - 10th Standards
A diameter is the longest chord possible, but that's not the only relationship between chords and diameters! Young geometry pupils construct perpendicular bisectors of chords to develop a conjecture about the relationships between chords...
Lesson Plan
EngageNY

The Distance from a Point to a Line

For Students 9th - 12th Standards
What is the fastest way to get from point A to line l? A straight perpendicular line! Learners use what they have learned in the previous lessons in this series and develop a formula for finding the shortest distance from...
Lesson Plan
Curated OER

Special Segments in Triangles

For Teachers 9th - 12th Standards
Students identify important properties of triangles. For this geometry lesson, students differentiate between medians, bisectors and altitudes in a triangle. They identify the properties of these important segments.
Assessment
Concord Consortium

In Oz We Tryst

For Students 9th - 11th Standards
The shortest distance from point A to point B is a straight line, but measuring distance gets more complicated when there are three points! Given the location of three friends, individuals determine the best point for all three friends...
Lesson Plan
Curated OER

Circumcenter of a Triangle

For Teachers 9th - 12th Standards
Your geometry learners will discover and show the construction of the circumcenter of a triangle. Guided by the steps in the activity, they construct perpendicular bisectors of each side that have a point of concurrency called the...
Lesson Plan
Curated OER

Reflections and Equilateral Triangles

For Teachers 9th - 10th Standards
Your learners collaboratively find the lines of symmetry in an equilateral triangle using rigid transformations and symmetry. Through congruence proofs they show that they understand congruence in terms of rigid motions as they...
Lesson Plan
Curated OER

Studying Special Segments in Triangles

For Teachers 8th - 10th
Students investigate special segments in triangles. In this geometry lesson plan, students graph, compare, estimate and predict findings based on their data. They differentiate between similarity and congruence of triangles.
Lesson Plan
Curated OER

Constructing Perpendiculars

For Teachers 9th - 10th
Students construct perpendicular lines. In this geometry lesson, students use a compass and straight edge to do construction. They start from a point to a line.
Lesson Plan
EngageNY

Designing a Search Robot to Find a Beacon

For Students 9th - 12th Standards
Build right angles using coordinate geometry! Pupils explore the concept of slope related to perpendicular lines by examining 90-degree rotations of right triangles. Learners determine the slope of the hypotenuse becomes the opposite...
Unit Plan
Mathematics Vision Project

Circles: A Geometric Perspective

For Teachers 10th - 12th Standards
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
Lesson Plan
Curated OER

Isosceles Triangles

For Teachers 9th - 10th
Students identify the properties of an isosceles triangle. In this geometry lesson, students find the midpoint, median and angle bisector of a triangle. They construct angle bisectors and measure missing angles.
Lesson Plan
Curated OER

Exploring Geometric Constructions of Parabolas

For Teachers 6th - 8th
Students are introduced to the construction geometrically of parabolas. Using a software program, they identify lines, segments and midpoints. They label the parabolas properties and characteristics and use a formula to determine the...
Lesson Plan
Curated OER

Slides, Flips. Turns......It's All On A Memory Book Page

For Teachers 4th
Fourth graders use tangram sets to investigate the congruence of shapes. They use congruent shapes to demonstrate the properties of slides, flips, and turns. They complete a math journal entry that describes and illustrates each concept.
Lesson Plan
EngageNY

The Definition of a Parabola

For Students 10th - 12th Standards
Put together the pieces and model a parabola. Learners work through several examples to develop an understanding of a parabola graphically and algebraically. 
Lesson Plan
Curated OER

Reflections and Equilateral Triangles II

For Teachers 9th - 10th Standards
Given the lines of symmetry in an equilateral triangle, your learners find where the pre-image vertices are mapped onto the new image. They explore the properties of equilateral triangles, the impact of reflections, and the...
Lesson Plan
Curated OER

Plenty of Pythagoras

For Teachers 5th - 8th
Using a twelve foot knotted rope, learners form a 3-4-5 right triangle. Following a discussion of observations about the lengths of the sides of the triangle, students use grid paper, scissors and a centimeter ruler to draw and measure...
Lesson Plan
Curated OER

Conjectures of Intersecting Circles

For Teachers 9th - 10th
Young scholars make conjectures of intersecting circles. In this geometry lesson, students observe circles and their position in space. They investigate and observe two and three dimensional objects.