# Math Help - Trig functions (very difficult)

1. ## Trig functions (very difficult)

please find the question in the attachment
its question no.4

2. Hello kandyfloss
Originally Posted by kandyfloss
please find the question in the attachment
its question no.4
Have a look at the diagram I've attached. I've shown all the distances you need. You need to:

• Calculate $\angle$ BAC, using the Cosine Rule on $\triangle$ ABC.
.
• Calculate $\angle$ BAR using the fact that $\triangle$ BAR is right-angled at R.
.
• Calculate $\angle$ CAS in a similar way
.
• Hence calculate $\angle$ PAT and finally the arc length PT

Can you complete it now?