Curated OER
Finding Angles in Right Triangles
In this geometry activity, 10th graders use right triangle trigonometry to solve application problems in which they find the measure of the missing angle in a right triangle. The two page activity contains five free response...
Curated OER
Section 8-6: Solving Problems Using Trigonometric Ratios
For this trigonometric ratios worksheet, high schoolers solve 20 short answer and multiple choice problems. Students use trigonometric ratios, the angle of depression, and angle of elevation to find missing side lengths of angles...
Curated OER
Area Measures and Right Triangles
Your class will investigate the relationship among different triangles. This geometry lesson, demonstrates how to make a connection between triangles and the Pythagorean Theorem. They identify the missing side or angle of a triangle.
Curated OER
Triangle Inequalities Homework
In this geometry worksheet, learners solve problems based on the triangle inequality theorem(s) in which determine if the given lengths can form a triangle, given two sides of a triangle determine the range of the third side, and order...
Curated OER
Area of a Triangle
Students solve the area of triangles. For this precalculus lesson, students are given two sides of a triangle and asked to calculate the area. They apply the law of sine and the side-angle-side area formula to solve.
EngageNY
Congruence Criteria for Triangles—AAS and HL
How can you prove it? Guide classes through an exploration of two possible triangle congruence criteria: AAS and HL. Learners connect this criteria to those previous learned and also explore criteria that does not work. The lesson...
Willow Tree
Interior Angles, Exterior Angles, and Diagonals of Polygons
How does the number of sides of a polygon affect the angle measures? Learners recognize a pattern in finding the total measure of interior and exterior angles and the number of diagonals. They use the patterns to calculate...
Alabama Learning Exchange
What You Know About the Bermuda Triangle?
Get lost in the classifications. Using the backdrop of the Bermuda Triangle, pupils classify it by angle and side measures. They also learn information about the triangle and its history.
Flipped Math
Unit 3 Review: Parallell and Perpendicular Lines
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...
EngageNY
Using Trigonometry to Determine Area
What do you do when you don't think you have enough information? You look for another way to do the problem! Pupils combine what they know about finding the area of a triangle and trigonometry to determine triangle area when they don't...
101 Questions
Best Triangle
What makes an equilateral triangle equilateral? It turns out it's much more than just the side lengths! Learners analyze four different triangles to determine the best equilateral triangle. They create a formula that they later use to...
Curated OER
Principles of Square Roots Lesson Plan
Middle and high schoolers investigate all the different places in math that square root is present. For this geometry lesson, pupils discuss square roots as it relates to a right triangle and construction. They go over altitude, rise,...
Curated OER
Learning About Triangles
Upper graders label four triangles and fill in the labels correctly. They draw three original triangles and answer the questions about them.
CK-12 Foundation
Angle-Side-Angle Triangles: Caution Tape
Don't lose your marbles. Scholars use an interactive to create a triangle that closes off a portion of a sidewalk with loose marbles. The Law of Sines helps them find the side measures of such a triangle.
Curated OER
Classifying Triangles
If you're looking for a presentation to assist you in your teaching of triangles, this one could be for you. In it, learners are shown how triangles are classified by the size of their angles and by their sides. These are tricky concepts...
Math Mammoth
Angles in a Triangle 2
Youngsters draw specified angles when given measurements of other angles and discover traits of angles in similar triangles. This one-page worksheet contains six multi-step problems.
Curated OER
Section 2.5 - Problem Solving (Part B)
Trying to figure out the perimeter of a geometric figure? Here are a few word problems to set up algebraic equations to solve for perimeter. There are also some word problems to set up algebraic equations to solve for angles in a...
Mt. San Antonio Collage
Congruent Triangles Applications
Triangles are all about threes, and practicing proving postulates is a great way to get started. The first page of the worksheet provides a brief introduction of the different properties and postulates. The remaining pages contain...
EngageNY
Triangle Congruency Proofs (part 2)
Looking to challenge your young scholars that have mastered basic triangle congruence proofs? A collection of proofs employ previously learned definitions, theorems, and properties. Pupils draw on their past experiences with proofs...
Mathematics Vision Project
Circles: A Geometric Perspective
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
Corbett Maths
Constructing SAS Triangles
Two sides and an angle ... a triangle it makes. Given the measure to two sides and the angle between them, the narrator of a short video shows how to draw a triangle with a ruler and protractor. Pupils use handouts to practice the newly...
Curated OER
Angles Activities
A series of geometry worksheets have mathematicians constructing, dissecting, overlapping, and measuring as they analyze angles in various contexts. Learners use symmetry and reflections in a compass rose to write instructions on...
EngageNY
Law of Sines
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...
Mathed Up!
Angles in Polygons
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...