Curated OER
Finding the Area of an Equilateral Triangle
The problem seems simple: find the area of the equilateral triangle whose sides are each length 1. In fact, this same problem is solved in 8th grade, addressing a different Common Core standard, using the formula for area of a triangle...
EngageNY
An Area Formula for Triangles
Use a triangle area formula that works when the height is unknown. The eighth installment in a 16-part series on trigonometry revisits the trigonometric triangle area formula that previously was shown to work with the acute triangles....
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...
CK-12 Foundation
Determination of Unknown Triangle Measures Given Area: Jib Sheets
Solving triangles is a breeze. Young boat enthusiasts solve problems involving triangles in the context of sails on a boat. They must apply different strategies, including the Law of Cosines and area formulas.
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...
Virginia Department of Education
Special Right Triangles and Right Triangle Trigonometry
Right triangles are so special! Use special right triangles to discover the trigonometric ratios. Pairs construct special right triangles and find the values of the ratios of the sides. In the process, they discover the ratios stay the...
Project Maths
Introduction to Trigonometry
The topic of trigonometric ratios is often covered with loads of rote memorization baked into the activity. This activity set, however, leans more on using similar triangles and discovery learning to help young geometers develop a deeper...
Radford University
Right Triangle Applications: Lessons 1 and 2
Use right triangles for more than just mathematical problems. The first two lessons of a unit ask pupils determine distances between cities by using the Pythagorean Theorem and a map. To cement understanding, learners use trigonometric...
CK-12 Foundation
Angle-Angle-Side Triangles: Garden Gate
Good fences make good gardens. Individuals use an interactive to see how angles and sides relate in a triangular-shaped garden fence. They apply the Law of Sines to find the length of the garden gate (third side of triangle) given two...
Curated OER
Trigonometry
In this geometry worksheet, 10th graders solve problems that are based on the right triangle trigonometry and the special right triangles. The three page worksheet contains twelve questions. Answers are not included.
Curated OER
Triangle Inequality Theorem
Students use the inequality theorem to solve triangles and their properties. In this geometry lesson, students are given spaghetti of different lengths and asked to create triangles. They conclude the necessary length needed to make a...
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...
Mathed Up!
Trigonometry
Learn how to solve a triangle. Young mathematicians view a video that explains how to apply trigonometry to find missing sides and angles of a right triangle. A activity tests their understanding of the concept.
Education Development Center
Similar Triangles
Model geometric concepts through a hands-on approach. Learners apply similar triangle relationships to solve for an unknown side length. Before they find the solution, they describe the transformation to help identify corresponding sides.
Curated OER
Algebra 2 & Trigonometry Practice: Law of Sines
In this law of sines worksheet, young scholars solve 9 multiple choice and short answer problems. Students use the law of sines to missing side lengths and angles of triangles.
Curated OER
Trigonometry Applications
In this geometry worksheet, 10th graders solve application word problems involving the use or right triangle trigonometry, including angle of elevation or depression. The one page interactive worksheet contains five questions. Hints,...
Curated OER
Right Triangles
In this right triangles worksheet, 10th graders solve 10 different problems that include various right triangles. First, they find the value of a base given its hypotenuse. Then, students determine an angle given the perimeter and...
Flipped Math
Unit 7 Review: Right Triangles
It is all right to spend some time with a review. After watching a short review video covering the materials from the unit, pupils work through 23 review problems. Scholars work on problems involving the Pythagorean Theorem and its...
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...
Curated OER
Inverse Trig Functions
Learners solve and graph 10 different problems that are the inverses of various trig functions. First, they determine which equation is equivalent to a given equation. Then, they find an angle of a right triangle, given its leg lengths....
Curated OER
Section 6.1-6.2 Precalculus: Trigonometry
For this trigonometry worksheet, high schoolers solve 15 triangle problems. Students use the law of sines and law of cosines to find the missing angles and side lengths of a triangles.
Curated OER
Easy Worksheet: Trigonometry
In this trigonometry worksheet, learners solve 4 short answer problems. Students find the sine, cosecant, secant or cotangent of an angle given a diagram of a right triangle with various measurements labeled.
Curated OER
Trigonometry
In this right triangles worksheet, students use trigonometric ratios to determine the length of a side of a triangle or a missing angle measurement. This two-page worksheet contains 20 problems.
Curated OER
Trigonometry Homework
In this right angles worksheet, students use trigonometric ratios to determine the length of a missing side or a missing angle of a right triangle. This two-page worksheet contains 19 problems.