Lesson Plans and Worksheets
Browse by Subject
Law of cosines Teacher Resources
Find teacher approved Law of Cosines educational resource ideas and activities
Students calculate the unknown sides and angles of a triangle and explore why one cannot determine the lengths of the sides of triangles if only the angles are known. Students explore the Law of Sines and the Law of Cosines by creating and measuring triangles. Students calculate the unknown sides by applying the correct formula.
In this cosine worksheet, students will find the length of the third side of a triangle given the length of the other two side. Students will use the Law of Cosines to find the length of the missing side. Answers will be rounded to 3 decimal places for the length and 1 decimal place for angle measures.
Students explore the concept of drafting. In this drafting lesson, students complete a project involving land surveying. Students refer to survey maps as they use the law of cosines and AutoCAD to construct drawings of the land survey. Students present their results to an "engineering firm" (the teacher) and to their class.