CK-12 Foundation
Relationships of Sides in 30-60-90 Right Triangles: Truck on a Mountain Road
Determine the change in elevation on a mountain road. Individuals use the interactive to simulate a truck driving up a mountain road with a 30-degree incline. They determine missing sides of a 30-60 right triangle to find horizontal and...
Flipped Math
Special Right Triangles I
Introduce a special relationship with right triangles. Learners discover the ratio of the sides in a 30-60-90 triangle. After watching several examples and seeing two different methods, pupils find unknown sides in triangles. Scholars...
West Contra Costa Unified School District
Investigating Special Right Triangles
Scholars first investigate relationships in the side lengths of 30°-60°-90° triangles and 45°-45°-90° triangles. This knowledge then helps them solve problems later in the lesson about special right triangles.
Curated OER
30-60-90 Right Triangles in Cabri Jr.
Young mathematicians draw and label right triangles using Cabri Jr. technology. They create other special right triangles and identify the length of the hypotenuse and each leg. High schoolers explore the ratios to determine how the...
Curated OER
Special Right Triangles Homework
In this geometry worksheet, students solve both kinds of special right triangles. There are 12 questions with multiple parts.
Curated OER
Special Right Triangles
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.
EngageNY
Sine and Cosine of Complementary Angles and Special Angles
Building trigonometric basics here will last a mathematical lifetime. Learners expand on the previous lesson in a 36-part series by examining relationships between the sine and cosine of complementary angles. They also review the ratios...
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...
Curated OER
Special Right Triangles
Using the Pythagorean Theorem to solve for missing angles, students evaluate right triangles and their properties.
Curated OER
Special Right Triangles
In this special right triangles worksheet, 10th graders solve 7 various problems with various types of right triangles. First, they identify the two special types of right triangles, the 45-45-90 degree triangle and the 30-60-90 right...
West Contra Costa Unified School District
Dilations Using Right Triangles
Don't argue with a triangle that has a 90-degree angle. It's always right. Scholars first use right triangles to help draw dilations of points. They continue the lesson by applying this skill to draw dilations of polygons.
Curated OER
Geometric Figures-Triangles
Fourth graders explore triangles. In this math lesson, 4th graders discuss the different types of triangles. Students create triangles using wiki sticks. Students complete an online matching game.
Curated OER
Trigonometric Functions of Acute Right Triangles
Students derive the six trigonometric functions. In this trigonometry activity, students show their understanding of trigonometric functions as they relate the right triangles. They find the missing angles and side use trig ratios of...
EngageNY
Prove the Pythagorean Theorem Using Similarity
Amaze your classes with the ability to find side lengths of triangles immediately — they'll all want to know your trick! Learners use the Pythagorean Theorem and special right triangle relationships to find missing side lengths.
Curated OER
Chapter 7 Final Review Extra Problems: Triangles
In this triangles worksheet, learners respond to 4 short answer problems. Students describe side relationships of different types of triangles. Learners find the area of a segment formed by a sector.
Curated OER
Tricky Triangle
In this triangle worksheet, students 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
Applying Special Right Triangles
In this geometry worksheet, 10th graders use the theorems regarding right triangles to find the missing length in a special right triangle. The one page worksheet contains eleven questions. Answers are included.
Curated OER
Geometric Properties
High schoolers find triangular angles using the angle theorem. In this geometry lesson plan, students describe labeled triangles, use the pythagorean theorem, and rewrite information about triangles in standard form.
EngageNY
From Circle-ometry to Trigonometry
Can you use triangles to create a circle? Learners develop the unit circle using right triangle trigonometry. They then use the unit circle to evaluate common sine and cosine values.
Curated OER
Classifying Triangles
In this classifying triangles learning exercise, learners explore given lengths or angle measurements and then classify each triangle as isosceles, scalene or equilateral. They also determine if the triangle may be right, acute or...
Curated OER
Triangles and Quadrilaterals
In this triangles and quadrilaterals worksheet, 10th graders solve 6 different problems related to using triangles and quadrilaterals in informal geometry. They determine how many lines of symmetry an equilateral triangle and an...
Curated OER
7-2 Self Check Pythagorean Theorem Multiple Choice
Middle and high schoolers use the Pythagorean Theorem to determine the length of the sides of a right triangle. They solve distance problems. This one-page worksheet contains 10 multiple-choice problems. This is self-checking worksheet.
Curated OER
Designing a Fort
Students explore the concept of right triangles. In this right triangle lesson, students construct a scale model of a tourist attraction similar to Fort Jefferson. Students research aerial photos of Fort Jefferson, then build their...
Curated OER
Special Right Triangles
Students identify different types of special right triangles. For this geometry lesson, students differentiate between right triangles and isosceles triangles. they construct the triangles using geometry software and make conjectures...