Illustrative Mathematics
Similar Triangles
Proving triangles are similar is often an exercise in applying one of the many theorems young geometers memorize, like the AA similarity criteria. But proving that the criteria themselves are valid from basic principles is a great...
Alabama Learning Exchange
Triangle Area: No Height? Use the Sine
No height? No problem! Learners use their knowledge and a little help from GeoGebra to develop the Law of Sines formula. The Law of Sines helps to determine the height of triangles to calculate the area.
Curated OER
Exploring Centers of a Triangle: Part 2
Students model and solve a real-world problem by constructing the centroid of a triangle. They explore relationships of the medians of a triangle and investigate how the centroid partitions each of the medians. Students investigate...
Curated OER
30-60-90 Right Triangles in Cabri Jr.
Young mathematicians draw and label right triangles using Cabri Jr. technology. They create other special right triangles and identify the length of the hypotenuse and each leg. Learners explore the ratios to determine how the hypotenuse...
EngageNY
Modeling Riverbeds with Polynomials (part 2)
Examine the power of technology while modeling with polynomial functions. Using the website wolfram alpha, learners develop a polynomial function to model the shape of a riverbed. Ultimately, they determine the flow rate through the river.
Curated OER
Exploring Characteristics of Triangles
Students draw triangles and explore the classification of each using the measures of interior angles and lengths of sides. They investigate the sum of the interior angles of various triangles and conjecture and prove the theorem: The...
Curated OER
Triangle Inequality Theorem
High schoolers investigate the relationship between angle measures and sides of a triangle and the relationships among the three sides of a triangle. The use of technology (Cabri, Jr.) allows learners to make and test conjectures as they...
Curated OER
Exploring Geometric Figures
Tenth graders explore mathematics by participating in hands-on daily activities. Learners identify a list of different shapes and classify them by shape, size, sides and vertices. They utilize tangrams and geometric pieces to gain an...
Texas Instruments
Getting Started with Cabri Jr.
Pupils construct geometric figures using Cabri Jr. in this constructing geometric figures using Cabri Jr. lesson. They familiarize themselves with Cabri Jr. and construct segments and triangles. Your learners will use various tools to...
Curated OER
Reflecting a Triangle in the Coordinate Plane
Learners explore geometric concepts using technology. They manipulate the TI to find important math topics. This activity requires a TI-84 or higher.
Curated OER
CORNER CABINET
Ninth and tenth graders calculate the length, width, height, perimeter, area, volume, surface area, angle measures or sums of angle measures of common geometric figures. They solve problems involving scale drawings, models, maps or...
EngageNY
Modeling Riverbeds with Polynomials (part 1)
Many things in life take the shape of a polynomial curve. Learners design a polynomial function to model a riverbed. Using different strategies, they find the flow rate through the river.
Curated OER
The Pythagorean Puzzle
An engaging hands-on activity is presented. Learners of all ages are addressed in thie unique plan. K-5 learners identify, name, and define a rectangle, square, triangle, and the concept of area. Older learners prove the Pythagorean...
Curated OER
Exploring Characteristics Needed to Prove Two Trianlges Congruent
Tenth graders explore congruent triangles. In this geometry lesson, 10th graders investigate the conditions necessary to prove two triangles congruent. The lesson combines dry erase board activities and the use of technology.
Alabama Learning Exchange
Technology for Displaying Trigonometric Graph Behavior: Sine and Cosine
Students explore the concept of sine and cosine. In this sine and cosine instructional activity, students work in groups to graph sine and cosine functions. Students examine how coefficients in various parts of each parent function...
Curated OER
Does Your Field Measure Up
Students measure angles using a plane table kit. In this geometry lesson, students use trigonometric identities to find the values of the length of a football field.
Curated OER
The Pythagorean Theorem
Learners create both a visual and formal proof of the Pythagorean theorem, as well as view four additional geometric demonstrations of the theorem. They construct a square and conjecture the following theorem: The sum of the areas of...
Curated OER
Rotations in the Plane
Pupils investigate the properties of a rotation as they use technology (Cabri, Jr.) to observe the relationship between the pre-image and the image formed by the rotation. The instructional activity provides ample opportunity for...
Curated OER
Unit on Spepherical Trigonometry
Tenth graders analyze characteristics and properties of two and three dimensional shapes. In this geometry lesson, 10th graders apply Spherical Easel Technology to help them decipher geometric shapes. They compare and contrast the 2D...
Curated OER
Tessellation Lesson Plan
Students produce original tessellations, using equilateral triangles where three unique symmetrical faces rotate, use shape, pattern/repetition, and color to create a striking composition, and create "beasties" inspired by bestiaries of...
Texas Instruments
Construction Regular Polygons
Learners investigate the process necessary to construct regular polygons. They explore the degree measures of the angles in a regular polygon. Using this information and technology in the form of Cabri Jr., your pupils will construct...
Curated OER
Matrix Madness!!
Perform operations to add, subtract, multiply and divide matrices. Then solve problems with vectors using matrices. A three day lesson: Matrix Madness, Mystical Matrices, and Decode the Encode. The last lesson has prizes that the class...
NTTI
Vectors: Traveling, But in What Direction
High schoolers watch a video of real-world situations regarding speed, direction, velocity, force, etc. and answer questions while viewing. They then practice drawing and using vectors to solve more real-world problems.
Curated OER
Geometry, Measurement & Reasoning
Learners measure prisms and determine their volume. In this measurement and reasoning lesson, students estimate the volume and area of prisms. They measure given boxes. Learners use paper to create prisms and cylinders. They determine...