Curated OER
Exploring Special Segments in Triangles
Young scholars discover that four special segments have a common intersection point. They identify the position of the intersection point in triangles. They produce conjectures about areas of the divided triangles.
Curated OER
Systems of Linear Inequalities
The class solves systems of linear inequalities. They graph lines and identify the point of intersection.They graph lines and identify the boundary that represent the solution and solution set.
Curated OER
Exploring the Circumcenter of a Triangle
Students construct the circumcenter of a triangle. For this constructing the circumcenter of a triangle lesson, students construct a triangle using Cabri Jr. Students draw perpendicular bisectors of the sides of the triangle. Students...
Curated OER
Exploring the Orthocenter of a Triangle
Young mathematicians explore the concept of triangles as they construct altitudes of triangles to find the orthocenter. Learners construct their triangles using Cabri Jr. on their graphing calculators and find that the altitudes of a...
Curated OER
Find Someone Who........
Fifth graders identify, describe, and classify lines, line segments, rays, and angles. When given a diagram of a line, they classify the line as perpendicular, parallel, intersecting, vertical, horizontal, and/or diagonal.
EngageNY
Translations
Learn through constructions! Learners examine a translation using constructions and define the translation using a vector. Pupils then construct parallel lines to determine the location of a translated image and use the vector as a guide.
EngageNY
Analytic Proofs of Theorems Previously Proved by Synthetic Means
Prove theorems through an analysis. Learners find the midpoint of each side of a triangle, draw the medians, and find the centroid. They then examine the location of the centroid on each median discovering there is a 1:2 relationship....
EngageNY
Properties of Area
What properties does area possess? Solidify the area properties that pupils learned in previous years. Groups investigate the five properties using four problems, which then provide the basis for a class discussion.
EngageNY
Finding Systems of Inequalities That Describe Triangular and Rectangular Regions
How do you build a polygon from an inequality? An engaging lesson challenges pupils to do just that. Building from the previous lesson in this series, learners write systems of inequalities to model rectangles, triangles, and even...
Willow Tree
Systems of Equations
Now that learners figured out how to solve for one variable, why not add another? The lesson demonstrates, through examples, how to solve a linear system using graphing, substitution, and elimination.
EngageNY
The General Multiplication Rule
In the first installment of a 21-part module, scholars build on previous understandings of probability to develop the multiplication rule for independent and dependent events. They use the rule to solve contextual problems.
EngageNY
Characteristics of Parallel Lines
Systems of parallel lines have no solution. Pupils work examples to discover that lines with the same slope and different y-intercepts are parallel. The 27th segment of 33 uses this discovery to develop a proof, and the class determines...
EngageNY
Rotations of 180 Degrees
What happens when rotating an image 180 degrees? The sixth activity in the series of 18 takes a look at this question. Learners discover the pattern associated with 180-degree rotations. They then use transparency paper to perform the...
Willow Tree
Functions
What makes a function a function? Learn the criteria for a relation defined as a function both numerically and graphically. Once young mathematicians define a function, they use function notation to evaluate it.
EngageNY
Inscribed Angle Theorem and Its Applications
Inscribed angles are central to the lesson. Young mathematicians build upon concepts learned in the previous lesson and formalize the Inscribed Angle Theorem relating inscribed and central angles. The lesson then guides learners to prove...
Illustrative Mathematics
Extensions, Bisections and Dissections in a Rectangle
Gaining practice in translating a verbal description into a diagram and then an equation is the real point of this similar triangles exercise. Once the diagram is drawn, multiple methods are provided to reach the conclusion. An effective...
EngageNY
Dividing Segments Proportionately
Fractions, ratios, and proportions: what do they have to do with segments? Scholars discover the midpoint formula through coordinate geometry. Next, they expand on the formula to apply it to dividing the segment into different ratios and...
EngageNY
Graphing Systems of Equations
Expand on learners' understanding of quadratic-linear systems. Building on the graphic understanding developed in the previous lesson, pupils learn algebraic methods of solving the systems.
EngageNY
Solving Exponential Equations
Use the resource to teach methods for solving exponential equations. Scholars solve exponential equations using logarithms in the twenty-fifth installment of a 35-part module. Equations of the form ab^(ct) = d and f(x) = g(x) are...
EngageNY
One-Step Problems in the Real World
Mirror, mirror on the wall, which is the fairest resource of them all? Individuals write and solve one-step equations for problems about angle measurement, including those involving mirrors. Both mathematical and real-world problems are...
Curated OER
Rotations
Young scholars discuss the concepts of reflection, rotation, and translation. In this rotation activity, students investigate rotations through examples on an overhead projector. No additional worksheet or student assignment is included.
Curated OER
Identifying Parallel and Perpendicular Lines
Students explore basic geometry. In this geometry lesson, students study points and lines that exist in flat planes. Students investigate parallel and perpendicular lines.
Curated OER
Graphing Solutions
In this graphing solutions worksheet, 9th graders solve 13 various types of problems. First, they find the solution of each systems by graphing on the coordinate plane provided. Then, students solve each systems of equations...
Curated OER
Exploring Angle/Pair Relationships
Students find missing angles and sides of triangles. For this geometry lesson, students create intersecting lines to measure angles. They use Cabri Software to create virtual angles.