EngageNY
Segments That Meet at Right Angles
Can segments be considered perpendicular if they don't intersect? Learners look at nonintersecting segments on the coordinate plane and make conclusions about the lines that contain those segments. They determine if they are...
Curated OER
The Pythagorean Theorem Lesson 2
Learners discuss and review examples of the Pythagorean Theorem using a GSP, Geometer's Sketchpad, activity.
Curated OER
Triangle Exterior Angles Theorem
Students identify the measure of missing exterior angles. For this geometry lesson,students define and apply the exterior angle theorem to solve problems. They use Cabri software to create different angles and make investigations.
Curated OER
How Do You Pay a Complement to an Angle?
Students observe and solve examples of the complementary angle theorem. They complete the How Do You Pay a Complement to an Angle worksheet, and write a response in their math journal.
Mathematics Vision Project
Similarity and Right Triangle Trigonometry
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...
EngageNY
Trigonometry and the Pythagorean Theorem
Ancient Egyptians sure knew their trigonometry! Pupils learn how the pyramid architects applied right triangle trigonometry. When comparing the Pythagorean theorem to the trigonometric ratios, they learn an important connection that...
Illustrative Mathematics
Trigonometric Ratios and the Pythagorean Theorem
Take an alternative route with trigonometry and let learners connect a tweaked version of the pythagorean theorem to the original in terms of triangle sides. The assignment leads participants towards deriving the Pythagorean identity...
EngageNY
Base Angles of Isosceles Triangles
Build confidence in proofs by proving a known property. Pupils explore two approaches to proving base angles of isosceles triangles are congruent: transformations and SAS. They then apply their understanding of the proof to more complex...
Mathed Up!
Angles: Parallel Lines
Viewers are presented with seven problems with parallel lines and angle relationships and must use the given information to find the measures of specific angles. To finish, they explain their process in finding the measures in the problems.
EngageNY
Solve for Unknown Angles—Transversals
Lead your class on an exciting journey through the world of math as they review geometry facts and solve for unknown angles. They learn how to use auxiliary lines and congruent angles to correctly complete each practice problem...
Willow Tree
Angle Sum Property of Triangles
All triangles have some things in common. Using these properties of triangles, learners find missing angle measures. Scholars use the Angle Sum Property and properties of special triangles throughout the instructional activity.
Mathematics Assessment Project
Identifying Similar Triangles
Math whizzes work with angle sums and exterior angles to figure out the measure of other angles. This particular publication provides comprehensive support in the form of an anticipatory activity, questions designed to prompt discussion,...
Curated OER
Angles and Arcs formed by Intersecting Chords
In this angles and arcs worksheet, students complete a warm-up, state the formula formed by intersecting chords, and answer eight problems. The worksheet includes a closing think pair share problem.
Curated OER
Angles and Similarity
High schoolers identify triangles as similar or congruent. In this geometry lesson, students drag triangles around on the navigator to see the effect of different angles on the shape of the triangle. They discuss angle similarity and...
Curated OER
Co-exterior Angles Worksheet
In this geometry worksheet, 10th graders analyze angles created by a transversal. They identify co-exterior angles as they review theorems dealing with parallel lines. There are 6 questions with an answer key.
Flipped Math
Pythagorean Theorem and Its Converse
Make sure it is all right in class. Pupils review the Pythagorean Theorem and find sides of right triangles, either by simplifying radicals or using calculators to find approximate lengths. Learners find out how to use the converse to...
Mathematics Vision Project
Module 4: Similarity and Right Triangle Trigonometry
Right you are to use a great resource. Starting with a lesson on dilations, scholars learn about similarity transformations and similar triangles. They use the knowledge to develop an understanding of right triangle trigonometry in later...
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.
Curated OER
Properties of Angles, Lines, and Triangles
In this properties of angles, lines and triangles instructional activity, 10th graders solve and complete 28 different problems that include determining the measurement of various figures shown. First, they use the geometric properties...
CK-12 Foundation
Pythagorean Theorem for Solving Right Triangles: Solving the Triangle
Observe the change in the trigonometric ratios as angles vary. An interactive provides the values of trigonometric ratios for both acute angles in a right triangle. Pupils create a right triangle to match given criteria and find the...
Curated OER
Pythagorean Theorem
In this Pythagorean theorem worksheet, 9th graders solve and complete 6 various types of problems. First, they find the length of a right-angled triangle's hypotenuse. Then, students determine which triangle is described and explain...
Curated OER
Pythagorean Theorem
For this Pythagorean theorem worksheet, students 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...
Curated OER
Triangle Sum Theorem
Teach your class how to solve problems using the triangle sum theorem. In this geometry instructional activity, young scholars identify the missing angles in a triangle using the sum theorem. They graph triangles on the TI and moves the...
Curated OER
The Pythagorean Theorem
In this geometry worksheet, 10th graders apply the Pythagorean Theorem as they determine the length of the missing leg or hypotenuse in right triangles. The one page worksheet contains twelve questions. Answers are included.