EngageNY
Fundamental Theorem of Similarity (FTS)
How do dilated line segments relate? Lead the class in an activity to determine the relationship between line segments and their dilated images. In the fourth section in a unit of 16, pupils discover the dilated line...
Virginia Department of Education
Angles, Arcs, and Segments in Circles
Investigate relationships between angles, arcs, and segments in circles. Pupils use geometry software to discover the relationships between angles, arcs, and segments associated with circles. Class members use similar triangles to...
Geometry Accelerated
Accelerated Geometry Review Sheet
Your geometry learners use their knowledge of various geometric concepts to write proofs. Starting with givens containing parallel line segments with transversals and triangles and quadrilaterals, and the mid-point and distance formulas;...
EngageNY
Informal Proofs of Properties of Dilations
Challenge the class to prove that the dilation properties always hold. The lesson develops an informal proof of the properties of dilations through a discussion. Two of the proofs are verified with each class member performing the...
EngageNY
Unknown Angle Proofs—Proofs of Known Facts
Lead the class in a Greek history lesson with a geometric twist. Pupils relate a short video about geometric properties to modern-day methods of solving for unknown angles. They discuss parallel line theorems and complete...
Illustrative Mathematics
Midpoints of the Sides of a Paralellogram
This task asks learners to prove that the segment joining the midpoints of two sides of a parallelogram is both congruent and parallel to an adjacent side of the parallelogram. The activity would be good to use in a discussion about how...
EngageNY
Interpreting and Computing Division of a Fraction by a Fraction—More Models
Use a unit approach in developing a fraction division strategy. The teacher leads a discussion on division containing units, resulting in a connection between the units and like denominators. Pupils develop a rule in dividing fractions...
EngageNY
Informal Proof of AA Criterion for Similarity
What does it take to show two triangles are similar? The 11th segment in a series of 16 introduces the AA Criterion for Similarity. A discussion provides an informal proof of the theorem. Exercises and problems require scholars to apply...
Curated OER
Transformations in the Coordinate Plane
Your learners connect the new concepts of transformations in the coordinate plane to their previous knowledge using the solid vocabulary development in this unit. Like a foreign language, mathematics has its own set of vocabulary terms...
Curated OER
Angles
Learners identify obtuse and acute angles in comparsion to a right angle. They identify obtuse, acute, and right angles. Pupils use "Shape Measure" to construct obtuse, acute, and right angles. They review line segements to locate right...
EngageNY
Unknown Angle Proofs—Proofs with Constructions
Provide your emerging mathematicians with the tools to learn as they incorporate auxiliary lines to solve unknown angle proofs in this continuing segment. They decipher information from a diagram to uncover the missing pieces and...
Federal Reserve Bank
The Fed's Role in Making and Setting Monetary Policy: Part 2
How does the Federal Open Market Committee work to formulate the nation's monetary policy in the United States? As the second segment of a lesson on the role of the Fed in setting monetary policy, class members will learn about open...
EngageNY
More About Similar Triangles
Determine whether two triangles are similar. The lesson presents opportunities for pupils to find the criterion needed to show that two triangles are similar. Scholars use the definition of similarity to find any missing side...
EngageNY
Reflections
Facilitate creativity in your math class as individuals learn the definition of a geometric reflection and correctly construct a model, as well as its reflected image. They use a perpendicular bisector and circles to elaborate on...
Curated OER
Reflections
Fifth graders create a reflection of a poygon using a Mira. They discover that a line connecting a vertiex of a polygon and the corresponding vertex of its reflection is perpendicular to the line of reflection. Students create a glide...
EngageNY
Complex Numbers and Transformations
Your learners combine their knowledge of real and imaginary numbers and matrices in an activity containing thirty lessons, two assessments (mid-module and end module), and their corresponding rubrics. Centered on complex numbers and...
Curated OER
Cartography Project
A lesson involving mapping, the use of a compass, writing and following directions, and exploring the first two themes of geography is here for you. Learners create original maps that show the routes they take through their own...
Virginia Department of Education
Arc Length and Area of a Sector
What do skateboarding and baked goods have in common with math? You can use them to connect half-pipe ramps and cakes to arcs and sectors. Pupils compare the lengths of three different ramp options of a skate park. They calculate the...
Curated OER
Tiling the Plane
Fifth graders use pattern blocks and triagular grid paper to reivew shape names, be introduced to the concept of a tiling of the plane, and determine which pattern blocks tile the plane. They are asked if they comprehend what a...