(Solved): The diagram below shows a circular tunnel with \( A B=8 \) metres and angle \( B A C=55^{\circ} \) ...

The diagram below shows a circular tunnel with \( A B=8 \) metres and angle \( B A C=55^{\circ} \). A platform is built in the tunnel from \( A \) to \( C \). Assume that angle \( B A Z= \) angle \( B C Z=90^{\circ} \). Find the width, \( A C \), of the platform in the tunnel. You may also assume that \( B Z \) is a diameter and is perendicular to \( A C \). Write the width in the box below and show your full working on your working paper. Platform width \( =\quad \mathrm{m} \) (give your answer correct to 2 decimal places)