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Lifewire: Excel Tan Function: How to Find the Tangent Angle

For Students 11th - 12th
This article shows you how to find the tangent angle using Excel. You may be able to accomplish this on a scientific calculator, but if you don't have one handy, Excel can help you make these calculations better than anything else.
Interactive
Curated OER

Zona Land: Right Triangle Solver 5

For Students 9th - 10th
A java applet that will solve a right triangle when you provide the lengths of side e (short side) and side f (hypotenuse).
Interactive
Curated OER

Zona Land: Right Triangle Solver 6

For Students 9th - 10th
A java applet that will solve a right triangle when you provide the lengths for side d (long side) and for side f (hypotenuse).
Interactive
Curated OER

Zona Land: Right Triangle Solver 1

For Students 9th - 10th
A java applet that will solve a right triangle when you provide information for angle D and its opposite side d.
Interactive
Curated OER

Zona Land: Right Triangle Solver 4

For Students 9th - 10th Standards
A java applet that will solve a right triangle when you provide side lengths for d (long side) and e (short side).
Interactive
Physics Aviary

Physics Aviary: Triangle Exploration Lab

For Students 9th - 10th
This lab is designed to have students look at some of the different relationships that exist in a right triangle. Students will be able to change the x-leg and y-leg of the triangle and then measure the angle and the hypotenuse of the...
Lesson Plan
Harvard University

University of Harvard: This Is a Stickup!

For Teachers K - 1st Standards
Students are taught how to make a sundial. The relationship between angles and the sides of a right triangle are explored. Great lesson plan ideas with plenty of background information. The instructional activity is adapted for grade...
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G C Right Triangles Inscribed in Circles Ii

For Teachers 9th - 10th Standards
For this task, students analyze the characteristics of a right triangle that has two sides labeled with midpoints and show that the triangle is inscribed in a circle with a diameter the length of its hypotenuse. Aligns with G-C.A.2.
Activity
University of Saskatchewan (Canada)

University of Saskatchewan: Trigonometric Functions

For Students 9th - 10th Standards
This site examines the six trigonometric functions from a right triangle point of view. Provides information, examples, and lots of exercises for understanding.
Handout
Purple Math

Purplemath: The Pythagorean Theorem

For Students 9th - 10th Standards
Defines the Pythagorean Theorem, and demonstrates how to use this Theorem in connection with right-angled triangles.
Unit Plan
Math Open Reference

Math Open Reference: Triangles

For Students 9th - 10th Standards
A complete reference guide to types of triangles and triangle perimeter and area. It provides definitions and interactive animated activities that enhance further explanation.
Handout
Calculator Soup

Calculator Soup: Pythagorean Theorem Calculator

For Students 9th - 10th Standards
This calculator solves the Pythagorean Theorem equation for sides a or b, or the hypotenuse c. The hypotenuse is the side of the triangle opposite the right angle.
Activity
Other

Ic Teachers: Shapes: Triangles

For Students 6th - 9th Standards
Are you looking for a very basic website that will explain the basic properties of a triangle? Use this site to learn about the properties of equilateral triangles, isosceles triangles, right triangles,and scalene triangles. There are...
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Gpe.5 Triangles Inscribed in Circle

For Teachers 9th - 10th Standards
For this task, students use ideas about linear functions to determine when certain angles are right angles. They use the fact that two lines (if not vertical or horizontal) are perpendicular when their slopes are inverse reciprocals, as...
eBook
Mathigon

Mathigon: Geometry: Triangles and Trigonometry: Pythagoras' Theorem

For Students 9th - 10th Standards
Pythagoras' Theorem: In any right-angled triangle, the square of the length of the hypotenuse (the side that lies opposite the right angle) is equal to the sum of the squares of the other two sides. (A+B=C)
Activity
Math2

Math2.org: Trigonometry Functions

For Students 9th - 10th Standards
A complete look at trig functions. From an "overview," page giving general definitions and important vocab words, to a listing of the 12 trig functions, to an explanation of the three modes used in trigonometry, to the procedures of how...
Handout
Purple Math

Purplemath: Basic Trigonometric Ratios: Examples

For Students 9th - 10th Standards
Demonstrates how to use trig ratios to do simple solving of triangles.