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Assessment
CPALMS

2D Rotations of Triangles

For Students 9th - 12th Standards
Where does the line of rotation need to be to get a cone? Pupils respond to three questions involving rotating a right triangle about different lines. The scholars describe the solid created along with providing details about its...
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Interactive
CK-12 Foundation

Ambiguous Case: Furniture Store Problems

For Students 10th - 12th
Remove any ambiguity about using a helpful resource. Individuals use an interactive to find the number of triangles that fit given conditions. They find that some conditions can result in more than one triangle in the ambiguous case.
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Interactive
CK-12 Foundation

Determination of Unknown Triangle Measures Given Area: Jib Sheets

For Students 10th - 12th Standards
Solving triangles is a breeze. Young boat enthusiasts solve problems involving triangles in the context of sails on a boat. They must apply different strategies, including the Law of Cosines and area formulas.
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Assessment
Illustrative Mathematics

Polygons

For Students 2nd Standards
Identify shapes based on their attributes. Second graders are tasked to color triangles, quadrilaterals, pentagons, and hexagons specific colors. The one thing these shapes have in common? They are all polygons.
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Unit Plan
Mathematics Vision Project

Congruence, Construction and Proof

For Teachers 9th - 10th Standards
Learn about constructing figures, proofs, and transformations. The seventh unit in a course of nine makes the connections between geometric constructions, congruence, and proofs. Scholars learn to construct special quadrilaterals,...
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Assessment
EngageNY

End-of-Module Assessment Task: Grade 7 Mathematics Module 6

For Students 7th Standards
Determine the level of understanding within your classes using a summative assessment. As the final lesson in a 29-part module, the goal is to assess the topics addressed during the unit. Concepts range from linear angle relationships,...
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Activity
Noyce Foundation

Lyle's Triangles

For Students K - 12th Standards
Try five problems on triangles. Levels A and B focus on shapes that can be created from right triangles. Level C touches upon the relationship between the area of a six-pointed star and the area of each triangle of which it is composed....
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Lesson Plan
Virginia Department of Education

How Many Triangles?

For Teachers 9th - 11th Standards
Something for young mathematicians to remember: the sum of any two sides must be greater than the third. Class members investigates the Triangle Inequality Theorem to find the relationship between the sides of a triangle. At the same...
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Assessment9:45
Mathed Up!

Angles in Polygons

For Students 8th - 10th Standards
Show your class that finding angle measures is a regular calculation with a resource that provides 12 problems dealing with the measures of angles in regular polygons. Pupils use formulas for the sum of measures of angles in a polygon to...
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Assessment
Illustrative Mathematics

Coordinates of Equilateral Triangles

For Students 9th - 12th Standards
Can it be constructed? The task poses the question whether it is possible to have an equilateral triangle with its vertices located at integer coordinates. Pupils work with their knowledge of trigonometric ratios and the Pythagorean...
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Lesson Plan
EngageNY

More on the Angles of a Triangle

For Students 8th Standards
Angles and triangles: they're all connected. Uncover the connections between angles in triangles. Scholars learn how to find both exterior and interior angle measures in triangles. The instructional activity emphasizes the vocabulary...
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Lesson Plan
EngageNY

Angle Sum of a Triangle

For Students 8th Standards
Prove the Angle Sum Theorem of a triangle using parallel line and transversal angle relationships. Pupils create a triangle from parallel lines and transversals. They find angle measures to show that the angles of a triangle must total...
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Lesson Plan
EngageNY

Law of Sines

For Teachers 11th - 12th Standards
Prove the Law of Sines two ways. The ninth segment in a series of 16 introduces the Law of Sines to help the class find lengths of sides in oblique triangles. Pupils develop a proof of the Law of Sines by drawing an altitude and a second...
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Assessment
Inside Mathematics

Circles in Triangles

For Teachers 9th - 12th Standards
Challenge the class with inscribed circles in triangles. The assessment task requests class members use their knowledge of circles and right triangles to prove two triangles are congruent. They go on to utilize their knowledge of...
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Assessment
Inside Mathematics

Hopewell Geometry

For Teachers 9th - 12th Standards
The Hopewell people of the central Ohio Valley used right triangles in the construction of earthworks. Pupils use the Pythagorean Theorem to determine missing dimensions of right triangles used by the Hopewell people. The assessment task...
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Assessment
Noyce Foundation

Parallelogram

For Teachers 6th - 7th Standards
Parallelograms are pairs of triangles all the way around. Pupils measure to determine the area and perimeter of a parallelogram. They then find the area of the tirangles formed by drawing a diagonal of the parallelogram and compare their...
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Assessment
Bowland

Rods and Triangles

For Teachers 6th - 9th
Scholars explore triangles with rods of different lengths. Using rods of 2, 4, 6, 8, and 10 cm class members build as many different types of triangles as they can. They also describe properties of these triangles and determine...
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Assessment
Bowland

Bunting

For Students 6th - 8th
How much fabric is necessary for bunting? Scholars use given dimensions of triangular bunting (hanging decorations) to determine the amount of fabric necessary to decorate a rectangular garden. The task requires pupils to consider how...
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Worksheet
PreKinders

Christmas Tree Pattern Block Mat

For Students Pre-K - 1st
Put the tree back in geometry! Explore shapes and celebrate Christmas while using pentagon, square, and triangle pattern blocks to create a Christmas tree.
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Lesson Plan
West Contra Costa Unified School District

Law of Sines

For Teachers 9th - 12th Standards
Laws are meant to be broken, right? Learners derive the Law of Sines by dropping a perpendicular from one vertex to its opposite side. Using the Law of Sines, mathematicians solve for various parts of triangles.
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Unit Plan
Mathematics Vision Project

Module 5: Modeling with Geometry

For Students 9th - 12th Standards
Solids come in many shapes and sizes. Using geometry, scholars create two-dimensional cross-sections of various three-dimensional objects. They develop the lesson further by finding the volume of solids. The module then shifts to finding...
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Activity
Teach Engineering

Straw Bridges

For Teachers 6th - 8th
Pairs work as engineering teams to design and build model bridges from drinking straws and tape. In this third segment in a series of 10, teams compete in an attempt to build the strongest bridge. To help with the design, the groups...
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Lesson Plan
Mathematics Assessment Project

Evaluating Statements About Length and Area

For Teachers 9th - 12th Standards
Class members complete an assessment task by identifying whether statements about triangles and quadrilaterals are always true, sometimes true, or never true. They then participate in a sorting activity with the same objective.
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Lesson Plan
Mathematics Assessment Project

Applying Angle Theorems

For Teachers 7th Standards
Polygon ... an empty bird cage? After finding the angles of a polygon, young mathematicians use the provided methods to solve the problem in multiple ways.