Sine rule and cosine ruleIB MYP Maths Extended: Mind map

Exam questions on Sine rule and cosine rule

1. In triangle $ABC$, $B\hat AC=40^\circ$, $A\hat BC=65^\circ$ and $BC=12$ cm.
   Explain why the cosine rule is not the best first step to find $AC$.2 marks
2. In triangle $PQR$, $PQ=6$ cm, $PR=10$ cm and $Q\hat PR=120^\circ$.
   Find the exact value of $\cos P\hat QR$.2 marks
3. Two points $A$ and $B$ are on a straight shoreline, 800 m apart. A boat is at the point $C$ out at sea, with $C\hat AB=52^\circ$ and $C\hat BA=71^\circ$.
   Find the distance $AC$ from the boat to the point $A$.3 marks