Lesson Plan
Virginia Department of Education

Special Right Triangles and Right Triangle Trigonometry

For Teachers 9th - 11th Standards
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...
Worksheet
Curated OER

Inverse Trig Functions

For Students 10th - 11th
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....
Lesson Plan
Curated OER

Solve Right Triangle

For Teachers 9th - 11th
In this trigonometric applications worksheet, students solve for the missing side of a right triangle using a trigonometric ratio. There are 46 questions, 10 of which are word problems.
Lesson Plan
Curated OER

Finding the Area of an Equilateral Triangle

For Teachers 9th - 11th Standards
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...
Instructional Video7:06
2
2
Flipped Math

Unit 7 Review: Right Triangles

For Students 9th - 12th Standards
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...
Worksheet
Curated OER

Special Right Triangles

For Students 9th - 12th
In this special right triangles worksheet, students solve 15 short answer problems. Students use trigonometric functions to find missing side lengths of various right triangles.
Worksheet
Curated OER

Determine the Measure of an Angle of a Right Triangle.

For Students 10th - 11th
In this geometry worksheet, students solve word problems by finding the values of missing angles and missing sides of triangles. They review their trigonometric properties of a right triangle. There are 9 problems with an answer key.
Worksheet
Curated OER

Trigonometry Ratios in Right Triangles

For Students 10th
In this trigonometry ratios in right triangles worksheet, 10th graders solve 10 different trigonometric ratios that apply to right triangles. First, they define a trigonometric ratio and its three most common ratios, sine, cosine, and...
Worksheet
Curated OER

Trigonometry Ratios in Right Triangles

For Students 10th
In this trigonometry ratios in right triangles worksheet, 10th graders solve 6 different right triangle problems. First, they find the values of x and y in each triangle, rounding each to the nearest tenth. Then, students locate the...
Worksheet
Curated OER

Special Right Triangles

For Students 10th
In this special right triangles worksheet, 10th graders solve 10 different problems that include solving equations that are special right triangles. First, they determine the exact value of each problem. Then, students use the...
Worksheet
Curated OER

Finding Trigonometric Ratios

For Students 11th
For this finding trigonometric ratios worksheet, 11th graders solve and complete 22 various types of problems. First, they find the value of each trigonometric ratio to the nearest ten-thousandth. Then, students use a calculator to find...
Worksheet
Curated OER

Sixteen Angle Pre-calculus Trig Problems

For Students 11th - Higher Ed
In this angle learning exercise, students solve ten multiple choice and six free response questions.  These precalculus questions cover angles, radians, and right triangles.
Worksheet
Curated OER

A Different Proof of the Law of Cosines

For Students 9th - 12th
In this proofs worksheet, students construct 1 proof of the law of cosines.  Students construct a right triangle within a circle to  prove the law of cosines.
Worksheet
Curated OER

Trigonometry Triangles

For Students 11th
In this trig instructional activity, 11th graders investigate the 6 trigonometry identities and their cofunctions. They use them to solve trig problems as related to right triangles. There are 5 questions with an answer key.
Worksheet
Curated OER

Trigonometry

For Students 10th - 12th
For 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.
Worksheet
Curated OER

Trigonometry Homework

For Students 10th - 12th
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.
Assessment
Inside Mathematics

Hopewell Geometry

For Teachers 9th - 12th Standards
The Hopewell people of the central Ohio Valley used right triangles in the construction of earthworks. Pupils use the Pythagorean Theorem to determine missing dimensions of right triangles used by the Hopewell people. The assessment task...
Worksheet
Curated OER

Easy Worksheet: Trigonometry

For Students 9th - 12th
In this trigonometry worksheet, students 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.
Worksheet
Curated OER

Trigonometric Ratios

For Students 10th
In this trigonometric ratios worksheet, 10th graders solve 9 different problems that include determining the trigonometric ratios of each triangle. First, they determine the sides and angles of a right triangle that is shown in each...
Lesson Plan
Willow Tree

The Pythagorean Theorem

For Students 8th - 11th Standards
There isn't a more popular geometry formula than the Pythagorean Theorem! Learners understand the special side relationships in a right triangle. They use the Pythagorean Theorem to find missing sides and to solve problems. They begin...
Worksheet
Curated OER

Tangents

For Students 9th - 12th
In this tangents worksheet, students determine the length of a missing side of a right triangles.  They use tangent lines to solve problems.  This two-page worksheet contains 11 multi-step problems.
Assessment
Mathed Up!

Trigonometry

For Students 10th - 12th
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 worksheet tests their understanding of the concept.
Interactive
Curated OER

Trigonometry Formula Worksheet

For Students 10th - 12th
In this trigonometry worksheet, students solve right triangle problems.  They find the sine, cosine and tangent of given triangles.  This on-line, interactive worksheet contains 6 problems.  Answers are provided.
Lesson Plan
EngageNY

Law of Sines

For Teachers 11th - 12th Standards
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...