Alabama Learning Exchange
"I Saw the Sine"
Discover trigonometric ratios that complement each other. Using two videos, the instructional activity introduces the trigonometric ratios. The class discovers the relationship between the sine and cosine of complementary angles.
Mathematics Assessment Project
Modeling Motion: Rolling Cups
Connect the size of a rolling cup to the size of circle it makes. Pupils view videos of cups of different sizes rolling in a circle. Using the videos and additional data, they attempt to determine a relationship between cup measurements...
Curated OER
Why Doesn't SSA Work?
Students investigate the relationship between angles and their sides. In this geometry lesson plan, students prove why SSA does not work as a true angle side relationship theorem.
EngageNY
Trigonometry and the Pythagorean Theorem
Ancient Egyptians sure knew their trigonometry! Pupils learn how the pyramid architects applied right triangle trigonometry. When comparing the Pythagorean theorem to the trigonometric ratios, they learn an important connection that...
Curated OER
Dilation
Tenth graders identidy and define various geometry terms, Students create exact replicas of a shape that is either smaller or larger than the original shape. Students prove that their entire shapes are larger or smaller in the same...
Curated OER
Introduction to Fractals: Geometric Fractals
Students explore the concept of fractals. In this fractals instructional activity, students discuss Sierpinski's Triangle using an applet. Students discuss the patterns involved with fractals. Students discuss the area of Sierpinski's...
Curated OER
NON-EUCLIDEAN GEOMETRY.
Students study relationships between angles, side lengths, perimeters, areas and volumes of similar objects. In this lesson students also create and critique inductive and deductive arguments concerning congruency, similarity and the...
Curated OER
Investigation: Area of Geometric Shapes
Fourth graders explore geometry by utilizing pattern blocks. In this pattern lesson, 4th graders analyze two separate pattern block shapes and discuss which one is bigger and smaller. Students collaborate in small groups to create...
Curated OER
Math: Tangents
Students discover how to recognize tangents and how to use their properties. They investigate and use the properties of angles, arcs, chords, tangents, and secants. Students use two tangents and the properties of similar triangles to...
EngageNY
Criterion for Perpendicularity
The Pythagorean Theorem is a geometry pupil's best friend! Learners explain the equation a1b1 + a2b2 = 0 for perpendicular segments using the Pythagorean Theorem. They are able to identify perpendicular segments using their endpoints and...
EngageNY
Scale Factors
Is it bigger, or is it smaller—or maybe it's the same size? Individuals learn to describe enlargements and reductions and quantify the result. Lesson five in the series connects the creation of a dilated image to the result. Pupils...
EngageNY
Cyclic Quadrilaterals
What does it mean for a quadrilateral to be cyclic? Mathematicians first learn what it means for a quadrilateral to be cyclic. They then investigate angle measures and area in such a quadrilateral.
Exploratorium
Exploring Pattern Blocks
Here's a great lesson that uses one of the best manipulatives there is: pattern blocks. Elementary schoolers must fill in a variety of shapes using specific amounts of pattern blocks. This forces them to do some spatial mathematical...
EngageNY
Definition of Congruence and Some Basic Properties
Build a definition of congruence from an understanding of rigid transformations. The lesson asks pupils to explain congruence through a series of transformations. Properties of congruence emerge as they make comparisons to these...
Curated OER
Tangrams
Students construct tangram pieces. Then they make observations and explore patterns with the pieces.
Curated OER
Tangrams
Learners construct the tangram pieces from a square paper by following directions to fold and cut. They make observations on the pieces formed and compare how they are related to each other. They explore patterns and shapes with the...