Lesson Plan
Curated OER

Triangle Shirtwaist Fire Tragedy

For Teachers 9th - 12th
Learners research the Triangle Shirtwaist Fire. In this labor reform lesson plan, students research the fire and write a newspaper article report from the perspective of the time. Learners evaluate the perspective of the workers and...
Worksheet
Curated OER

Triangle Trigonometry IB Packet

For Students 11th - 12th
In this trigonometry worksheet, students use triangle trignometry to solve problems in order to find the missing length, angle, or area of the triangle. The one page worksheet contains five ...
Lesson Plan
Curated OER

Triangle Fire and Labor Movement

For Teachers 10th
Tenth graders, in groups, explore the garment industry before, during, and after the Triangle Shirtwaist Fire to learn about the Labor Movement, unions, and some of the people who impacted working conditions for both adults and children...
Worksheet
Curated OER

The Triangle Midsegment Theorem

For Students 10th
In this geometry worksheet, 10th graders identify the vocabulary associated with the Triangle Midsegment Theorem and solve problems in which they find the size of a missing angle or segment.  The one page worksheet contains nineteen...
Worksheet
Curated OER

Using Triangles To Make Shapes

For Students 3rd - 4th
In this using triangles instructional activity, students create quadrilaterals and hexagons. In this problem solving instructional activity, students draw as many quadrilaterals and hexagons as possible.
Worksheet
Curated OER

Identifying Triangles

For Students 7th - 9th
In this triangles practice worksheet, students respond to 4 questions that require them to identify the pictured triangles as acute, right, obtuse, scalene, isosceles, or equilateral triangles.
Worksheet
Curated OER

Isosceles Triangles

For Students 3rd - 4th
In this isosceles triangles worksheet, students cut or count the triangles on this sheet. Students cut or count out 13 isosceles triangles that are all different colors.
Printables
Math Salamanders Ltd.

2D Shape Sheet Triangles

For Students K - 2nd Standards
In this triangles worksheet, students can cut out or count the triangles given to them. Students cut or count 13 different colored triangles.
Worksheet
Guru Promotions Pty Ltd.

Shapes Worksheet: Triangles

For Students Pre-K - K Standards
Work on drawing and identifying triangles with a math activity. After kindergartners trace triangles at the top of the page, they draw their own versions underneath, and color the triangles that are hidden amid other geometric shapes.
Unit Plan
1
1
Mathematics Vision Project

Similarity and Right Triangle Trigonometry

For Teachers 10th - 12th Standards
Starting with similar triangles and dilation factors, this unit quickly and thoroughly progresses into the world of right triangle features and trigonometric relationships. Presented in easy-to-attack modules with copious application...
Lesson Plan
EngageNY

Proof of the Pythagorean Theorem

For Teachers 8th Standards
What does similarity have to do with the Pythagorean Theorem? The activity steps through the proof of the Pythagorean Theorem by using similar triangles. Next, the teacher leads a discussion of the proof and follows it by an animated...
Assessment
Balanced Assessment

Refiguring Pythagoras

For Students 6th - 8th
Why was Pythagoras so obsessed with squares? The assessment task posits the question of whether the geometric interpretation of the Pythagorean Theorem holds for figures other than squares. Scholars first consider the case of semicircles...
Lesson Plan
EngageNY

The Converse of the Pythagorean Theorem

For Teachers 8th Standards
Is it a right triangle or not? Introduce scholars to the converse of the Pythagorean Theorem with a lesson that also provides a proof by contradiction of the converse. Pupils use the converse to determine whether triangles with given...
Lesson Plan
Virginia Department of Education

Pythagorean Theorem

For Students 8th Standards
Investigate the meaning of the Pythagorean Theorem through modeling. After comparing the area of the square of each side, individuals cut triangles and squares to facilitate the comparison.
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,...
Lesson Plan
EngageNY

Unknown Angles

For Students 9th - 10th Standards
How do you solve an equation like trigonometry? Learners apply their understanding of trigonometric ratios to find unknown angles in right triangles. They learn the meaning of arcsine, arccosine, and arctangent. Problems include...
Lesson Plan
Mathematics Assessment Project

Deducting Relationships: Floodlight Shadows

For Teachers 9th - 12th Standards
Try to figure out what happens with shadows as a person moves between two light sources. A formative assessment lesson plan has individuals work on an assessment task based on similar triangles, then groups them based on...
Lesson Plan
EngageNY

From Circle-ometry to Trigonometry

For Students 10th - 12th Standards
Can you use triangles to create a circle? Learners develop the unit circle using right triangle trigonometry. They then use the unit circle to evaluate common sine and cosine values.
Unit Plan
Arizona Department of Education

Area and Perimeter of Regular and Irregular Polygons

For Teachers 3rd - 6th Standards
Extend young mathematicians' understanding of area with a geometry lesson on trapezoids. Building on their prior knowledge of rectangles and triangles, students learn how to calculate the area of trapezoids and other...
Lesson Plan
EngageNY

Modeling Using Similarity

For Teachers 8th Standards
How do you find the lengths of items that cannot be directly measured? The 13th installment in a series of 16 has pupils use the similarity content learned in an earlier resource to solve real-world problems. Class members determine...
Lesson Plan
Illustrative Mathematics

Two Wheels and a Belt

For Teachers 9th - 10th Standards
Geometry gets an engineering treatment in an exercise involving a belt wrapped around two wheels of different dimensions. Along with the wheels, this belt problem connects concepts of right triangles, tangent lines, arc length, and...
Worksheet
Mathwire

Shamrock Paths

For Students 7th - 10th Standards
What could St. Patrick's Day and Pascal's triangle possibly have in common? Trace the pattern in a holiday-themed worksheet that prompts learners to find the word shamrock as many times as they can.
Worksheet
DK Publishing

Draw the Shape ~ Counting Triangles

For Students K - 1st Standards
Starting simply, scholars begin by tracing two triangles before drawing one or two on their own. Next, they examine three pictures to determine how many triangles they see in each. Learners record their answers, practicing writing...
Lesson Plan
1
1
Illustrative Mathematics

Bank Shot

For Teachers 9th - 11th Standards
Young geometers become pool sharks in this analysis of the angles and lengths of a trick shot. By using angles of incidence and reflection to develop similar triangles, learners plan the exact placement of balls to make the shot....

Other popular searches