Cosine rule practice
Two sides of a triangle are \(3\) and \(8\), with included angle \(60^\circ\). Use the cosine rule to find \(c^2\) and the missing side \(c\).
Worked practice: cosine rule
Substitute the included angle into the cosine rule, simplify c squared, then take the positive side length.
Write a full answer
Now write the response in full, in your own words — this is what the exam asks for. The AI marks it on the same moves you built above (focus, evidence, technique, judgement) and gives feedback on reasoning, evidence, and expression.