Illustrative Mathematics
Extensions, Bisections and Dissections in a Rectangle
Gaining practice in translating a verbal description into a diagram and then an equation is the real point of this similar triangles exercise. Once the diagram is drawn, multiple methods are provided to reach the conclusion. An effective...
Mathematics Assessment Project
Deducting Relationships: Floodlight Shadows
Try to figure out what happens with shadows as a person moves between two light sources. A formative assessment lesson has individuals work on an assessment task based on similar triangles, then groups them based on their assessment...
Curated OER
Triangle Inequality Theorem
Students use the inequality theorem to solve triangles and their properties. In this geometry instructional activity, students are given spaghetti of different lengths and asked to create triangles. They conclude the necessary length...
Illustrative Mathematics
Tangent to a Circle From a Point
Learners see application of construction techniques in a short but sophisticated problem. Combining the properties of inscribed triangles with tangent lines and radii makes a nice bridge between units, a way of using information about...
Houghton Mifflin Harcourt
Introducing the Concept: Triangles and Quadrilaterals
Guide your geometers through the process of constructing polygons. They learn how to draw triangles, squares, parallelograms, rectangles, rhombuses, and trapezoids with specified angles using a protractor and a ruler. The lesson plan...
Curated OER
Getting It Right!
Students construct right triangles, measuring the sides and recording the measurements in spreadsheets. They analyze their measurements for patterns and research the Internet for information on Pythagoras.
Houghton Mifflin Harcourt
Developing the Concept: Triangles and Quadrilaterals
Exact narrative and examples make this lesson on polygons easy to implement. Through it, your class will learn how to use a protractor and ruler to construct triangles and quadrilaterals according to your directions. Your class will be...
Curated OER
Constructing Triangles
In this constructing triangles online worksheet, students construct thirteen triangles on paper first and then type in their answers on line. Students can check their answers as they go and the computer calculates the overall score for...
Curated OER
Hands On: Construct Triangles and Rectangles
In this congruent triangles and rectangles worksheet, students solve 6 word problems where they identify whether triangles and rectangles are congruent, and construct triangles. Students must explain their reasoning and prove each answer.
Curated OER
Triangles
In this triangles learning exercise, 10th graders solve 3 extensive informal geometry problems that involve triangles. First, they sketch a triangle, selecting 3 of the sides and constructing 3 midpoints. Students then draw each of 3...
Curated OER
Congruent Triangles
Young scholars explore the concept of congruent triangles. In this congruent triangles lesson, students use Cabri Jr. to construct two congruent triangles using circles. Young scholars determine if the two triangles are congruent by...
Curated OER
Triangle Congruence
Students use web applet to create congruent triangles. In this geometry lesson, students differentiate between congruent and similar. They create shapes online and drag those shapes around to create visuals of triangles.
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
Exploring the Centroid of a Triangle
Pupils examine the centroid of a triangle as they use Cabri Jr. to construct a triangle and its medians. The dynamic nature of the software allows learners to measure the lengths of the segments in the triangle and conjecture and verify...
Mathematics Vision Project
Circles: A Geometric Perspective
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
West Contra Costa Unified School District
Law of Sines
One must obey the sine laws. A lesson introduces and derives the Law of Sines for non-right triangles. With examples that use the Law of Sines to determine unknown measures in triangles, the lesson checks to see if the Law of Sines also...
Radford University
Building a Recreation Center
It's all about location, location, location. Small groups work to find the best spot for a rec center to serve three different communities. Learners construct the inscribed and circumscribed circles of a triangle to find the best place....
Curated OER
Triangles
Students identify triangles in the real world and construct their own triangle using drinking straws. They explore abstract triangles and find additional geometric shapes such as trapezoids. Students discuss similar shapes and examine...
MathMovesU
Practice: Measuring Angles and Using a Protractor and More!
Four fabulous worksheets are included in this resource, all having to do with the measurement of angles. On the first, anglers will use a protractor to determine the degrees of 10 different angles. An arc is drawn on each. On the second,...
Curated OER
Constructions of Isosceles and Equilateral Triangles
Learners explore the difference between drawing and constructing a triangle utilizing The Geometer's Sketchpad on the computer. They create, develop and script constructions for both isosceles and equilateral triangles. Each student has...
Curated OER
Family Activity: Triangles and Quadrilaterals
In this triangles and quadrilaterals worksheet, students solve 7 short answer problems. Kids find objects around the house that are constructed from triangles, parallelograms, trapezoids, squares, rectangles. Students sketch the object...
Curated OER
Geometry: Basic Constructions
In this geometry learning exercise, 10th graders use a straightedge and a compass to construct congruent segments and angles, bisect a segment and an angle, construct perpendicular and parallel lines, construct tangents, circumscribe a...
Curated OER
Geo Shapes
First graders listen as the book, "Try It With Triangles" is read to the class. They name the geometric shapes that they see in the story and view the Shape Vocabulary Cards as they name them from the book. They then cut out the...
Curated OER
Triangle Exploration
Students are introduced to The Geometer's Sketchpad software while in the computer lab. They focus on triangles, horizontal lines, vertex and top parallel lines. Each student utilizes geometry to complete basic geometric constructions.