Geometry Help
Geometry Help: Tangent Lines
Explains the basic concept of congruent triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Illustrative Mathematics
Illustrative Mathematics: G Srt, G Mg How Far Is the Horizon?
Some friends are at the beach looking out onto the ocean on a clear day and they wonder how far away the horizon is. A second problem asks how far the horizon would be from the top of a mountain. Students must also answer a question...
Illustrative Mathematics
Illustrative Mathematics: G C Two Wheels and a Belt
A certain machine is to contain two wheels, one of radius 3 centimeters and one of radius 5 centimeters, whose centers are attached to points 14 centimeters apart. The manufacturer of this machine needs to produce a belt that will fit...
Sophia Learning
Sophia: Two Lines Tangent to a Circle: Lesson 3
This lesson will present how if two segments from the same point outside a circle are tangent to a circle, then they are congruent. It is 3 of 5 in the series titled "Two Lines Tangent to a Circle."
ClassFlow
Class Flow: Circles Geometry
[Free Registration/Login Required] Students identify segments and lines related to circles and the properties of a tangent to a circle.
Texas Instruments
Texas Instruments: Angles Formed by Intersecting Chords, Secants, and Tangents
In this activity, students will investigate properties of angles and arcs formed when chords, secants, and tangents intersect and intercept arcs in a circle. They discover several important theorems concerning circles and arc sizes. They...
CK-12 Foundation
Ck 12: Tangent Lines
[Free Registration/Login Required] Students can adjust the size of the circle to explore the tangent lines. Click learn more to watch a video and click challenge me to answer a practice question.
Clark University
Clark University: Dave's Short Trig Course: Trigonometric Functions
The Clark University site shows and explains the graphs of the six trigonometric functions. It explains how to find an arbitrary angle measurement using trig. Also, it explains that sine and cosine functions are complementary.
Illustrative Mathematics
Illustrative Mathematics: g.c Inscribing a Circle in a Triangle I
The goal of this task is to show how to draw a circle which is tangent to all three sides of a given triangle: that is, the circle touches each side of the triangle in a single point. Aligns with G-C.A.3.
University of Regina (Canada)
Univeristy of Regina: Math Central: Tangent Lines and Circle Equations
This site offers a problem and solution to finding all possible slopes for a line tangent to a circle given a particular equation of a circle. Could be an interesting challenge for students.
Varsity Tutors
Varsity Tutors: Hotmath: Practice Problems: Conic Sections
Hotmath provides 26 practice problems relating to conic sections. Each of the practice problems include a step-by-step guide for solving their conic.
Purple Math
Purplemath: Inverses of Trigonometric Ratios
You know that you can take side lengths and find trig ratios, and you know you can find trig ratios (in your calculator) for angles. What is missing is a way to go from the ratios back to the original angles. And that is what "inverse...
Geometry Help
Geometry Help: Chords
Explains the basic concept of chords with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: La Circunferencia
In Spanish. This interactive unit could be used as a visual review of circles, circumference and tangents.
Illustrative Mathematics
Illustrative Mathematics: G Srt Ask the Pilot
In the July 2013 issue of United Airlines' Hemisphere Magazine, a pilot responded to a question about how far in the distance he could see at different altitudes. The solution involved right triangles, lines of tangency to a circle, and...
Illustrative Mathematics
Illustrative Mathematics: F Tf Special Triangles 1
Using known facts about the unit circle and isosceles triangles together with the Pythagorean Theorem, students can derive the sine and cosine of special angles. Aligns with HSF-TF.A.3.
Illustrative Mathematics
Illustrative Mathematics: F Tf Special Triangles 2
Using known facts about the unit circle and isosceles triangles together with the Pythagorean Theorem, students can derive the sine and cosine of special angles. Aligns with HSF-TF.A.3.
Other
Dans Math: Lessons: Trigonometry
College professor Dan Bach reviews basic trig concepts, including trig functions, right triangles, circles, radians, and polar coordinates. Site includes animated graphs and detailed examples.
Illustrative Mathematics
Illustrative Mathematics: F Tf Equilateral Triangles and Trigonometric Functions
The purpose of this task is to apply knowledge about triangles to calculate the sine and cosine of 30 and 60 degrees. Aligns with HSF-TF.A.3.
Math Is Fun
Math Is Fun: Introduction to Trigonometry
Students are introduced to concepts taught in trigonometry. The tutorial consists of notes and examples.
Oswego City School District
Regents Exam Prep Center: Formulas for Angles in Circles
Formulas and illustrations show the different kinds of angles created by intersecting tangents, secants, radii, and in combination.
Calculator Soup
Calculator Soup: Trigonometric Functions Calculator
This online trigonometry calculator will calculate the sine, cosine, tangent, cotangent, secant and cosecant of angle values entered in degrees or radians. The trigonometric functions are also known as the circular functions.
Calculator Soup
Calculator Soup: Trigonometric Functions Calculator
This online trigonometry calculator will calculate the sine, cosine, tangent, cotangent, secant and cosecant of values. The trigonometric functions are also known as the circular functions.
Math2
Math2.org: Trigonometry Tables
Three trig tables are provided for student and teacher reference. The first table lists the sine, cosine, tangent, secant, cosecant, and cotangent values of all whole-number angles from 0 to 90. The radian equivalent (to four decimals)...