Use this worksheet if you need to focus solely on using the Cosine rule to find missing angles in non-right-angled triangles.
In Section A, students start by labelling triangles appropriately, ensuring they can correctly identify sides and angles before applying the formula.
Section B introduces guided problems where students complete missing steps in cosine rule calculations to determine unknown angles. The fill-in-the-gaps format reinforces the correct sequence of operations while allowing students to focus on understanding how the formula works.
Section C presents more challenging problems where students apply the cosine rule independently to calculate unknown angles. One problem involves solving for two angles, extending the difficulty level.
This worksheet is effective because it provides a clear progression from guided practice to independent problem-solving. The variety of question formats makes it a valuable resource for classwork, revision, or homework.