CK-12 Foundation
Bisectors of Line Segments and Angles: Cut a Line
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...
CK-12 Foundation
Midpoint and Segment Bisectors: Midpoint Map
Discover how to find a midpoint with a conceptual exploration. Scholars manipulate a point to determine the location of a midpoint on a straight line distance between two locations. Later questions extend to determine the...
Curated OER
Cabri Jr. Perpendicular Bisector of a Chord
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...
Curated OER
Perpendicular Bisector of a Line Segment
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...
EngageNY
Characterize Points on a Perpendicular Bisector
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...
Curated OER
Perpendicular Bisector Theorem
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.
Curated OER
Dividing Line Segments into n Congruent Parts
Students identify lines, and line segments. In this geometry lesson plan, students divide line segments into equal congruent parts. They complete a laboratory activity dealing with lines and segments.
Curated OER
IGD: Perpendicular Bisector
Students 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. Students...
EngageNY
Special Lines in Triangles (part 2)
Medians, midsegments, altitudes, oh my! Pupils study the properties of the median of a triangle, initially examining a proof utilizing midsegments to determine the length ratio of a median. They then use the information to find missing...
CK-12 Foundation
Bisectors of Line Segments and Angles: Cut an Angle
Explore constructions through an interactive online lesson. Given an example of an angle bisector construction, learners investigate the markings to determine the method used. Challenge questions help solidify the steps.
Curated OER
Concurrent Lines in Triangles
Learners explore the concept of concurrent lines in triangles. In this concurrent lines in triangles lesson, students work in groups to investigate properties of concurrent lines in acute, right, and obtuse triangles. Learners use a...
Mathematics Vision Project
Circles: A Geometric Perspective
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...
Illustrative Mathematics
Points equidistant from two points in the plane
Young geometers apply their deductive reasoning skills and knowledge of proving triangles congruent in a task that asks them to prove if a point lies on the perpendicular bisector of a segment, then it is equidistant from the endpoints...
EngageNY
Definition of Reflection and Basic Properties
Discover the results of reflecting an image. Learners use transparency paper to manipulate an image using a reflection in this fourth lesson of 18. They finish by reflecting various images across both vertical and horizontal lines.
Curated OER
Constructing Perpendicular Bisectors
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...
Curated OER
Contructions and Conjectures
Students make constructions and conjectures. In this geometry lesson, students construct right, acute and obtuse angles using a straight edge and a protractor. They investigate parallel lines and the angles formed by the angles.
Curated OER
Circles and Angles
Young scholars identify tangents, chords and secants. In this geometry lesson, students graph circles and identify angles created by secant lines, tangent lines and chords.
Curated OER
Constructing Perpendiculars
Students construct perpendicular lines. In this geometry lesson plan, students use a compass and straight edge to do construction. They start from a point to a line.
Curated OER
Diagonals to Quadrilaterals II
Students identify the properties of different polygons. For this geometry lesson, students find the slope of a line and calculate the distance between two lines. They differentiate between similar and congruent polygons.
Curated OER
Conjectures For Intersecting Circles
Students identify properties of circles. In this geometry lesson, students identify the center of two intersecting circles.They use Cabri software to create circles and move it around to make observation.
EngageNY
Circles, Chords, Diameters, and Their Relationships
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...
Texas Instruments
Properties of Parabolas
Explore the properties of parabolas in this lesson. Construct a parabola given a focus and a directrix on the Ti-Nspire. Write equations of parabolas in vertex form and determine the a value of a parabola given a focus and directrix.
Curated OER
Circumcenter of a Triangle
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...
California Mathematics Project
Reflections
Reflections are the geometric mirror. Pupils explore this concept as they discover the properties of reflections. They focus on the coordinates of the reflections and look for patterns. This is the third lesson in a seven-part series.