EngageNY
Applying the Laws of Sines and Cosines
Breaking the law in math doesn't get you jail time, but it does get you a wrong answer! After developing the Law of Sines and Cosines in lesson 33 of 36, the resource asks learners to apply the laws to different situations. Pupils must...
Illustrative Mathematics
Are They Similar?
Learners separate things that just appear similar from those that are actually similar. A diagram of triangles is given, and then a variety of geometric characteristics changed and the similarity of the triangles analyzed. Because the...
K-5 Math Teaching Resources
2-D Shape Cards
Add some visual support to your elementary geometry lessons with this set of printable shape cards. From triangles and squares to octagons and nanogons, this simple resource can be used in countless ways to develop children's knowledge...
EngageNY
Putting the Law of Cosines and the Law of Sines to Use
Use the Law of Cosines and the Law of Sines to solve problems using the sums of vectors. Pupils work on several different types of real-world problems that can be modeled using triangles with three known measurements. In the process,...
Curated OER
You Can't Go Wrong with a Right Triangle 1
Fourth and fifth graders study the Pythagorean Theorem and apply it to find the missing side of a right triangle.
Curated OER
Special Triangles and Quadrilaterals
In this special triangles worksheet, students examine given special triangles. They determine the length of a missing side and/or the measurement of a missing angle for given triangles and quadrilaterals. Students justify...
Raytheon
Understanding Triangles
In this understanding triangles worksheet, learners read 6 pages of examples and explanations about identifying triangles, determining length of sides and degrees of angles, including the hypotenuse, then answer 28 questions, answers...
Curated OER
Angular Size and Similar Triangles
In this angular size and similar triangles activity, students use the properties of similar triangles and the ratios of sides to solve for unknowns in given diagrams.
Curated OER
Pythagorean Theorem
In this geometry worksheet, 10th graders solve for missing sides and angles of a triangle. They use the pythagorean theorem to solve for the unknown in a right triangle. There are 5 questions on this worksheet.
Curated OER
Proving Pythagoras
Students prove the theorem of Pythagoras. In this Pythagorean Theorem instructional activity, students define the different parts of a right triangle. They use the Pythagorean Theorem to solve for the missing sides and angles of a right...
University of Adeaide
Basic Trigonometry and Radians
A fabulous set of examples and problems that introduce basic trigonometry concepts, this packet is set apart by the care it takes to integrate both radians and degrees into the material. After defining radians, the author demonstrates...
EngageNY
Converse of the Pythagorean Theorem
Discover a new application of the Pythagorean Theorem. Learners prove and apply the converse of the Pythagorean Theorem in the 17th instructional activity in a 25-part series. The examples ask learners to verify right triangles...
K12 Reader
Shapes on a Plane
Geometric shapes are the focus of a comprehension exercise that asks readers to examine a short passage about planes, circles, triangles, and rectangles, and then to respond to a series of questions about the article.
Mathematics Vision Project
Module 6: Congruence, Construction, and Proof
Trace the links between a variety of math concepts in this far-reaching unit. Ideas that seem very different on the outset (like the distance formula and rigid transformations) come together in very natural and logical ways. This...
Curated OER
Similarity and Dilations - Discover Properties of Similar Figures
Learners investigate properties of similar figures. In this properties of similar figures lesson, pupils construct similar figures using Cabri Jr. They dilate their figure to create a similar one, and discuss the relationships between...
K12 Reader
The Art of M.C. Escher
Show your class one way in which art and math are related by teaching them about M.C. Escher. Class members read a brief passage and then respond to five related questions.
Curated OER
Number of Solutions for a Triangle
In this solutions for a triangle worksheet, students use trigonometric ratios to determine the number of triangles that can be constructed with the given sides and angles. This one-page worksheet contains 22 problems.
Curated OER
Tricky Triangle
In this triangle instructional activity, high schoolers solve 1 word problem about the lengths of a triangle. Students determine the length of the longest side given the ratio of the angle measures.
Curated OER
Geometry of Triangles Using a Protractor
Seventh graders use a protractor to measure angles and solve a problem involving distance. For this measuring angles with a protractor lesson plan, 7th graders calculate the distance of a line on a diagram by using a protractor to...
Illustrative Mathematics
Midpoints of the Sides of a Paralellogram
This task asks learners to prove that the segment joining the midpoints of two sides of a parallelogram is both congruent and parallel to an adjacent side of the parallelogram. The activity would be good to use in a discussion about how...
Inside Mathematics
Circles in Triangles
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...
Curated OER
Geometry Practice: G.G.28 #1: Congruent Triangles
In this congruent triangles worksheet, students solve four multiple choice problems. Students determine which statement is the appropriate reasoning to say that two triangles are congruent.
EngageNY
Conditions for a Unique Triangle—Two Angles and a Given Side
Using patty paper, classes determine that only one triangle is possible when given two specific angle measures and a side length. As the 10th instructional activity in the series of 29, young math scholars add these criteria to those...
Curated OER
Shapes and Angles
Are your geometry whizzes learning about angles and shapes? This online worksheet gives 10 multiple choice questions based on images and word problems. Concepts include deducting angle degree, classifying shapes, and identifying angle...