This worksheet provides a structured approach to applying the cosine rule to calculate missing side lengths in non-right-angled triangles. The worksheet is divided into three sections.
In Section A, students start by labelling the triangles correctly, reinforcing their understanding of how the cosine rule applies to different cases. This step ensures they are familiar with identifying given values and unknowns before performing calculations.
Section B presents structured problems where students complete missing steps in cosine rule calculations. The fill-in-the-gap format helps them focus on the sequence of operations while reinforcing correct formula application.
Section C includes more challenging problems where students must apply the cosine rule independently to find missing side lengths.
This worksheet is highly effective as it builds understanding progressively, allowing students to develop confidence before tackling complex problems. The mix of guided and independent questions makes it a valuable resource for class practice, revision, or homework.