Krzysztof Haft-Szatynski
Move the Turtle
Turtles are not known to be speedy movers, but have you ever tried to get them to move in a specific direction? How about getting them to move in a perfect circle? With this app, young computer programmers have to be on their toes to...
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....
Curated OER
Length, Perimeter, and Area
Learners explore the concepts of length, perimeter, and area. In this math activity, students use Shape Explorer to practice finding length, perimeter, and area.
Curated OER
The Pythagorean Theorem
Students research Pythagoras and learn how to apply his theorem. They solve real life problems using the theorem and demonstrate knowledge of exponents, equations, and radicals. Students include diagrams in their research papers.
Curated OER
A Rectangle in the Coordinate Plane
A quadrilateral is drawn on the coordinate plane, and eighth grade geometers find the length of each side and the diagonals by applying the Pythagorean theorem.
Math Mammoth
Triangles
A six-page packet walks, or bends learners through angles that combine to create triangles. Definitions are given for right triangles, obtuse and acute triangles. They draw angles according to directions, using a protractor to meet the...
Curated OER
Aurora Borealis
In this Aurora Borealis worksheet, students read about how early scientists used triangulation to measure the height of the Aurora Borealis. Students solve 3 problems using triangulation.
Curated OER
Constructions and Loci
In this geometry worksheet, students construct polygons and calculate the different angles formed by each shape. They construct circles, trapezoids, and rectangles and answer 20 questions.
Curated OER
Triangle Conjectures
Tenth graders investigate the theorems of ASA, AAS, AAA and ASA. For this geometry lesson, 10th graders discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how two angles are formed by...
Curated OER
Quadrilaterals
In this geometry worksheet, 10th graders solve problems with quadrilaterals. They calculate the sum of the angles, find missing angles and identify properties of quadrilaterals. There are 16 questions with an answer key.
Curated OER
Triangles Congruency Theorems
Tenth graders investigate the theorems of ASA, AAS, AAA and ASA. In this geometry lesson, 10th graders discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how two angles are formed by...
Curated OER
Let's Gather Around the Circle
Scholars explore the relationship between circumference and diameter. Groups of learners measure the diameter and circumference of round objects and record their data on a given worksheet. They then input the data into their graphing...
Curated OER
Investigating the Slopes of Parallel and Perpendicular Lines
High schoolers investigate parallel and perpendicular lines. They use Cabri Jr. to construct and explore the relationships between the slopes of parallel and perpendicular lines. The drawing and measurement tools available with Cabri Jr....
Curated OER
Arc Length and Sectors
Find the length of an arc. Students relate central angles to the area and length of a sector and graph circles on the TI to make predictions.
Curated OER
Picking Pythagoras
Students discover that side measurement is used in determining angle classification of a triangle. By squaring sides, they predict whether triangles be right, obtuse, or acute. They prove the Pythagorean Theorem and use it to solve...
Curated OER
Triangle Sum Theorem
Tenth graders investigate the theorems of angles and lines to prove triagle sum theorem. For this geometry lesson, 10th graders discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how...
Curated OER
Tessellations
Students learn and review basic geometric terms, definitions, and theory, including regular polygons, lines, angles, points, etc. They make a tessellating stamp and create a repeating work of art.
Curated OER
Introduction to Field Mapping with a Compass and Pace
Students practice using compass and calibrate their own pace, take field measurements of pre-set course with compass and pace, convert measurements into map, using angles and vectors, and make composite class map by adjusting different...
Curated OER
Pythagorean Theorem
Students discover the Pythagorean Theorem. In this discovering the Pythagorean Theorem lesson, students measure the lengths of various triangles to the nearest centimeter. Students record their measurements in a table. ...
Curated OER
Similar Figures
In this geometry worksheet students explore similar polygons and determine measure of missing sides and angles. Students use indirect measurement with similar triangles and determine the area and volume of similar figures. The seven...
Curated OER
Midsegments of Quadrilaterals
High schoolers explore the concept of quadrilaterals as they find the midsegments of quadrilaterals using Cabri Jr. on a graphing calculator. They find midpoints, slopes, angles, and distances of lines and angles.
Curated OER
Investigating Segments in a Right Triangle
High schoolers explore the concept of right triangles as they construct a right triangle using Cabri Jr. Learners find the midpoint of the hypotenuse and construct a line from the midpoint to the vertex of the right angle. They then...
Curated OER
Let the Sun Shine In: Energy Conservation
Students create a project applying their math skills as they discuss energy conservation. In this geometry lesson, students define vocabulary relating to the environment and energy conservation. They construct a building that allow lots...
Curated OER
Points, Lines, and Distance
Young scholars calculate the distance between two points. In this geometry lesson, students define the meaning of the distance between parallel lines. They find the point of intersection of other lines.