Cosine Rule – Finding Lengths

Cosine Rule – Finding Lengths
Cosine Rule – Finding Lengths
Cosine Rule – Finding Lengths
Cosine Rule – Finding Lengths

What's Included

  • Smart Notebooks Presentation
  • Interactive Excel File
  • Activ Inspire Flipchart
  • Lesson Plan
  • Microsoft PowerPoint Presentation
  • Differentiated Worksheet

Cosine Rule – Finding Lengths

Students learn how to derive and apply the Cosine rule to find missing lengths in triangles.  As learning progresses they are challenged to apply multiple formulae involving triangles to solve more complex problems.
Differentiated Learning Objectives
  • All students should be able to calculate an unknown length in a non right-angled triangle using the Cosine rule.
  • Most students should be able to calculate a magnitude of direction using bearings and a length in a non right-angled triangle using the Cosine rule.
  • Some students should be able to derive and apply the Cosine Rule to calculate unknown lengths in triangle shapes.
View online lessonLesson DownloadsDownload PowerPoint Download Notebook Download Flipchart Download WorksheetDownload Interactive Excel File
Scheme of Work Link
Trigonometry - Non-Right-Angled Triangles
Related Blog
Solving Problems with Non-Right-Angled Triangles 
IMMEDIATE DOWNLOAD

You may also like...

Pythagoras’ Theorem – Shorter Sides

Students learn how to calculate a shorter side of a right-angled triangle using Pythagoras' Theorem.  As learni...

Pythagoras’ Theorem – Finding the Hypotenuse

Students learn how to derive and apply Pythagoras' Theorem to find the hypotenuse of right-angled triangles.  A...

Exact Trigonometric Solutions

Students learn how to solve trigonometrical equations with exact solutions using special triangles.   As learnin...

Mr Mathematics Blog

Mathematics OFSTED Inspection – The Deep Dive

Earlier this week, my school took part in a trial OFSTED inspection as part of getting ready for the new inspection framework in September 2019. This involved three Lead Inspectors visiting our school over the course of two days. The first day involved a ‘deep dive’ by each of the Lead Inspectors into Mathematics, English […]

How to Solve Quadratics by Factorising

The method of how to solve quadratics by factorising is now part of the foundational knowledge students aiming for higher exam grades are expected to have.   Here is an example of such a question. Solve x2 + 7x – 18 = 0 In my experience of teaching and marking exam papers students often struggle with […]

How Write 3 Part Ratios

When learning how to write 3-part ratios students need to understand how ratios can be made equivalent. The start of the lesson reminds students by asking which of six ratios is the odd one out.  This is presented to the class as they come into the lesson.    Writing Equivalent Ratios  A few students immediately go […]