+
Interactive
Shodor Education Foundation

Squaring the Triangle

For Students 8th - 12th Standards
Teach budding mathematicians how to square a triangle with an interactive that shows a graphical proof of the Pythagorean Theorem. Pupils alter the lengths of the legs using sliders. Using the inputted lengths, the applet displays the...
+
Lesson Plan
Curated OER

Geometry Journal: Isosceles Triangles

For Teachers 10th - 12th
In this isosceles triangles worksheet, students justify and determine the symmetry of an isosceles triangle. They explore the bisector of rectangles. This three-page worksheet contains two problems. Answers are listed on page three.
+
Instructional Video5:17
2
2
Flipped Math

Unit 3 Review: Parallell and Perpendicular Lines

For Students 9th - 12th Standards
Learners watch a quick review on the Parallel and Perpendicular Lines unit. The pupils work through ten review problems ranging from identifying types of angles formed by parallel lines and transversals to writing equations of parallel...
+
Workbook
1
1
Utah Education Network (UEN)

Geometric Figures and Scale Drawings

For Students 7th Standards
Scale up your lessons on geometry and ask learners to investigate conditions on triangles, scale drawings, the area and circumference of circles, and angle relationships. The resource includes activities and a homework assignment.
+
Lesson Plan
Curated OER

The Pythagorean Theorem Lesson 2

For Teachers 8th - 12th
Learners discuss and review examples of the Pythagorean Theorem using a GSP, Geometer's Sketchpad, activity.
+
Lesson Plan
Curated OER

Discover the Pythagorean Theorem

For Teachers 6th - 8th
Pupils explore the Pythagoras theorem. In this geometry instructional activity, students make right triangles and identify the parts of the triangle. Pupils complete measurements of the sides of the triangle.
+
Lesson Plan
Curated OER

Exploring Pythagorean Theorem

For Teachers 8th
Eighth graders explore the Pythagorean Theorem. They use Geometer's Sketchpad and explore features of various figures. Students use the software to build a figure using the given measurements.
+
Lesson Plan
Curated OER

Angles in Triangles

For Teachers 8th
Eighth graders translate word problems using mathematical ideas. For this geometry lesson, 8th graders identify angles of triangles using equations and the triangle sum theorem. They create angles with a protractor and straight edge.
+
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...
+
Unit Plan
Mathematics Vision Project

Module 3: Geometric Figures

For Teachers 9th - 12th Standards
It's just not enough to know that something is true. Part of a MVP Geometry unit teaches young mathematicians how to write flow proofs and two-column proofs for conjectures involving lines, angles, and triangles.
+
Worksheet
Curated OER

Properties and Attributes of Polygons

For Students 10th
For this geometry worksheet, 10th graders determine if a polygon is convex or concave and apply the polygon Angle sum theorem and the polygon exterior angle sum theorem to determine the measures of interior and exterior angles of a...
+
Lesson Plan
1
1
Illustrative Mathematics

Right Triangles Inscribed in Circles I

For Teachers 9th - 10th Standards
One of the basic properties of inscribed angles gets a triangle proof treatment in a short but detailed exercise. Leading directions take the learner through identifying characteristics of a circle and how they relate to angles and...
+
Worksheet
Geometry Accelerated

Accelerated Geometry Review Sheet

For Students 8th - 10th Standards
Your geometry learners use their knowledge of various geometric concepts to write proofs. Starting with givens containing parallel line segments with transversals and triangles and quadrilaterals, and the mid-point and distance formulas;...
+
Assessment
Charleston School District

Pre-Test Unit 2: Similar and Congruent

For Students 8th Standards
A pre-test contains questions about transformations that lead to congruent and similar images. It also covers angle relationships associated with triangles and parallel lines intersected by a transversal. 
+
Lesson Plan
Curated OER

Exploring Characteristics of Triangles

For Teachers 9th - 11th
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...
+
Lesson Plan
EngageNY

The Binomial Theorem

For Teachers 11th - 12th Standards
Investigate patterns in the binomial theorem. Pupils begin by reviewing the coefficients from Pascal's triangle. They look at the individual terms, the sums of the coefficients on a row, and the alternating sum of each row. Individuals...
+
Lesson Plan
1
1
Curated OER

A Rectangle in the Coordinate Plane

For Teachers 7th - 9th Standards
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. 
+
Lesson Plan
Curated OER

Triangles Congruency Theorems

For Teachers 10th
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...
+
Worksheet
Curated OER

Pythagorean Theorem

For Students 9th - 10th
In this Pythagorean theorem worksheet, learners solve and complete 20 different problems that include using the Pythagorean theorem to solve them. First, they use the Pythagorean theorem to determine the value of x in each right...
+
Worksheet
Curated OER

Triangle Similarity

For Students 10th
In this triangle similarity worksheet, 10th graders solve and complete 12 different problems that include defining similar and 3 similar statements using only sides and angles. First, they determine if each pair of triangles shown are...
+
Worksheet
Curated OER

Properties of Angles, Lines, and Triangles

For Students 10th
In this properties of angles, lines and triangles worksheet, 10th graders solve and complete 28 different problems that include determining the measurement of various figures shown. First, they use the geometric properties and theorems...
+
Lesson Plan
EngageNY

Similar Triangles in Circle-Secant (or Circle-Secant-Tangent) Diagrams

For Teachers 9th - 12th Standards
First angle measures, now segment lengths. High schoolers first measure segments formed by secants that intersect interior to a circle, secants that intersect exterior to a circle, and a secant and a tangent that intersect exterior to a...
+
Lesson Plan
Curated OER

Pythagorean Theorem

For Teachers 6th - 10th
In this Pythagorean theorem worksheet, students use the Pythagorean theorem to find the missing side of the triangle. Students complete 10 problems.
+
Lesson Plan
Curated OER

Geometric Properties

For Teachers 9th - 12th
Students find triangular angles using the angle theorem. In this geometry instructional activity, students describe labeled triangles, use the pythagorean theorem, and rewrite information about triangles in standard form.