Curated OER
Cosines
In this online math worksheet, learners practice finding the cosines given 10 different sets of data. When complete, students submit their answers and get instant feedback regarding their accuracy.
Curated OER
The Law of Cosines
In this Law of Cosines learning exercise, students are asked to demonstrate the ability to apply the Trigonometric Law of Cosines and the Inverse Law of Cosines to solve for sides and angles of right triangles.
Wolfram Research
Wolfram Math World: Obtuse Triangles
MathWorld.com offers information on obtuse triangles and links to related terms and formulas.
Wolfram Research
Wolfram Math World: Acute Triangle
This MathWorld site gives a short discussion on acute triangles with links to related terms and topics. The site offers a discussion on the least number of acute triangles to compose various polygons, and a discussion on the relationship...
Math Open Reference
Math Open Reference: Triangles
A complete reference guide to types of triangles and triangle perimeter and area. It provides definitions and interactive animated activities that enhance further explanation.
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)...