6.06 Problem solving with trigonometry

A suspension bridge is being built. The top of the concrete tower is $76.2$76.2 metres above the bridge and the connection point for the main cable is $29.6$29.6 metres from the tower. The concrete tower and the bridge are perpendicular to each other.

If the angle the cable makes with the road is $a$a, find $a$a to two decimal places.