National Research Center for Career and Technical Education
Architecture and Construction: Stair Construction
Within the context of the construction industry, algebra pros begin to calculate slope from the sizes of stair steps. This is a terrific lesson, especially for aspiring engineers. Just be aware that it might be a stretch to meet all of...
Curated OER
Radian Measure
Young mathematicians identify central angles, arcs and radius of circles in this pre-calculus lesson. They identify the proportion of the circle based on its radius while they convert between degrees and radians measurements.
Center for Innovation in Mathematics Teaching
Trigonometry
This unit covers the basic trigonometry including understanding radians, how to convert between radians and degrees, the area of a circle subtended by an angle, basic properties and graphs of sine, cosine, tangent, and solving...
Curated OER
Reference Angles
Learn how to measure the reference angles in degrees and radians. Young scholars find reference angles that are coterminal with a given angle.
Curated OER
Trigonometry Realms
Excellent site reviewing the realms of Trigonometry. Topics Include the trig functions, graphs, right triangles and much more.
Math Medics
S.o.s. Math: Measure of an Angle
This lesson gives a tutorial on the measure of an angle. Includes sample problems and solutions.
University of Colorado
University of Colorado: Ph Et Interactive Simulations: Trig Tour
Take a tour of trigonometry using degrees or radians! Look for patterns in the values and on the graph when you change the value of theta. Compare the graphs of sine, cosine, and tangent.
Varsity Tutors
Varsity Tutors: Hotmath: Practice Problems: Trigonometric Functions
Hotmath provides 24 practice problems relating to trigonometric functions. Each of the practice problems include a step-by-step guide for solving their function.
Varsity Tutors
Varsity Tutors: Hotmath: Practice Problems: Right Angle Trigonometry
Fourteen problems present practice working with right angle trigonometry. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the problem then click the "View Solution" button to check...
Windstream
Ojk's Precalculus Study Page: Measurement of Angles
An introduction to radian measurement, including converting between radians and degrees. Includes several examples and lots of pictures.
University of Georgia
University of Georgia: Arcs, Central Angles, Arc Length & Sector Area
This site provides practice problems for calculating central angles and calculating arc length.
Wolfram Research
Wolfram Math World: Cut the Knot! Angles
Very good site with links to reviews of various angles.
Texas Instruments
Texas Instruments: Relation Between Central Angle and Inscribed Angle Measure
Students investigate the relationship between measure of central and inscribed angles in a circle.
Texas Instruments
Texas Instruments: Math Today When a Ruler Isn't Enough
This activity illustrates a real-life problem that uses trigonometry to solve for an unknown. students can use trigonometric ratios and inverse trigonometric relationships to determine the side of a triangle and the measure of the...
Texas Instruments
Texas Instruments: What's the Trig?
Students will be introduced to right triangle trigonometry. They will use the TI-89 and Geometer's Sketchpad to construct a right triangle and calculate sin, cosine, and tangent of various acute angles.
Analyze Math
Analyze Math: Special Angles on Unit Circle
Learners explore the special angles between 0 and 2 pi on a unit circle. The special angles can be used to solve trigonometry problems.
Northeast Parallel Architectures Center, Syracuse University
Npac Reu Program: Radians
Northeast Parallel Architectures Center of Syracuse University offers a quick overview of radian measurement of angles. Also includes an example.
Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: Razones Trigonometricas De Angulos Obtuse
In Spanish. Learn how to calculate trigonometric ratios of angles greater than 90 degrees.
Math Planet
Math Planet: Algebra 2: Angles
Features a definition, examples, and a video lesson all related to angles. [0:35]
Math Planet
Math Planet: Algebra 2: Cosines
Defines and explores the law of cosines through examples and a video lesson. [1:41]
Mangahigh
Mangahigh: Shape: Use Trigonometry to Find Angles
Use trigonometry to determie the angle measures.
Mangahigh
Mangahigh: Shape: Use the Law of Sines for Finding Angles
Test your knowledge of using the law of sines to determine angle measures.
CK-12 Foundation
Ck 12: Trigonometry: Coterminal Angles
[Free Registration/Login may be required to access all resource tools.] Defining and identifying coterminal angles.
CK-12 Foundation
Ck 12: Trigonometry: Radian Measure
[Free Registration/Login may be required to access all resource tools.] Define Radian Measure and Critical Angles in Radians.