Curated OER
Inscribed Angles
Students analyze inscribed angles and intercepted arcs and explore the relationships between the two. They investigate the properties of angles, arcs, chords, tangents, and secants to solve problems involving circles.
Curated OER
Estimating Angles
Sixth graders estimate the measurement of angles and linear distance from one point to another. Using a specified website, 6th graders play a game of "Golf" where they enter the angle and distance a ball must be hit. Upon completion of...
EngageNY
Solving Problems Using Sine and Cosine
Concepts are only valuable if they are applicable. An informative resource uses concepts developed in lessons 26 and 27 in a 36-part series. Scholars write equations and solve for missing side lengths for given right triangles. When...
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...
EngageNY
Converse of the Pythagorean Theorem
Discover a new application of the Pythagorean Theorem. Learners prove and apply the converse of the Pythagorean Theorem in the 17th lesson in a 25-part series. The examples ask learners to verify right triangles using the converse of the...
Virginia Department of Education
The Pythagorean Relationship
Add up areas of squares to discover the pythagorean relationship. Small groups create right triangles with squares along each side. They calculate the areas of each square and notice the relationship. Groups construct other types of...
National Security Agency
Partying with Proportions and Percents
Examine ratios and proportions in several real-world scenarios. Children will calculate unit rates, work with proportions and percentages as they plan a party, purchase produce, and take a tally. This lesson plan recommends five...
Mathematics Assessment Project
Estimating Volume: The Money Munchers
Don't stuff money under your mattress. To find out why learners first complete a task determining how $24,000 in cash would affect the height of a mattress and whether this same amount would fit into a suitcase of given dimensions. They...
Curated OER
Triangles: Triangle Inequalities
Using SketchPad on their calculators to construct triangles, students measure exterior angles and remote interior angles of their constructed triangle. Students develop the triangle inequality from observation and exploration with their...
Shodor Education Foundation
Volume of Prisms
Explore the concept of volume of prisms using an applet to perform the calculations. The link to the interactive applet is embedded into the lesson plan as well as a link to associated data sheets. Get your math class to the computer lab...
Shodor Education Foundation
Surface Area of Rectangular Prism
With this interactive lesson, learners compute the surface area of rectangular prisms. They visit an online investigation applet and record data on the provided handout. Pair this lesson with the volume lesson by the same publisher as an...
Curated OER
Angles: Angles, Angles, Everywhere
Students estimate and accurately measure the size of angles communicate with the appropriate geometric terms and symbols to describe and name angles, lines, line segments, rays
Curated OER
Bisecting Angles and Segments
Students bisect angles and segments using a mira. They measure the original angles and segments and the angles and segments formed by bisecting to better see the relationship between them.
Curated OER
How High did My Rocket go?
Students shoot off a rocket and measure the trig ratios relation. In this geometry lesson, students practice using an inclinometer to figure out how high their rockets fly. They measure angles and height and relate it to gravity and...
Curated OER
Surface Area with Polydrons
Students explore measurements by analyzing geometric shapes. In this surface area lesson, students identify the terms volume, weight, perimeter and area in order to find the requested measurements of specific polygons. Students utilize...
Curated OER
Introducing Trigonometry
Eleventh graders explore the three basic trigonometric functions. In this trigonometry/Algebra II lesson, 11th graders use GeoGebra and the unit circle to define the ratios of sides is a right triangles as they examine the full domain...
Curated OER
Angle Benchmarks
Sixth graders discuss the characteristics of specific angles and then use the information to to identify and estimate given angles. The class goes outside, identifies north, and turns a specified amount of degrees. Using a given compass,...
Curated OER
Reflection of Light With Two Plane Mirrors- Double Mirrors Placed at a Number of Angles
Students place two plane mirrors at different angles to experiment with reflection. They make kaleidoscopes and periscopes.
Curated OER
Angle Aerobics
Third graders review angle criteria and then stand. They demonstrate with their hands each type of angle called out by the teacher: right, acute, or obtuse. Music is added and students follow teacher in an angle aerobics class peppered...
Curated OER
Automobile-Accident Reconstruction
Students investigate an accident and relate it to math. In this trigonometry lesson, students measure the accident scene, the friction produced, and the speed from the skid marks. They create a poster of their findings.
Curated OER
Measuring the Earth (Eratoshenes' method)
Sixth graders engage in problem solving, communicating, reasoning, and connecting to represent and solve problems, using geometric models.
EngageNY
The Definition of Sine, Cosine, and Tangent
Introduce your classes to a new world of mathematics. Pupils learn to call trigonometric ratios by their given names: sine, cosine, and tangent. They find ratios and use known ratios to discover missing sides of similar triangles.
Illustrative Mathematics
Eratosthenes and the Circumference of the Earth
The class gets to practice being a mathematician in ancient Greece, performing geometric application problems in the way of Eratosthenes. After following the steps of the great mathematicians, they then compare the (surprisingly...
Willow Tree
Common Geometric Figures
Geometry could be called the study of figures. An overview of the figures found in a typical geometry course contains a study of different triangles, quadrilaterals, and regular polygons.