I need help please. I don't quite understand it! "How are we ever going to build this bridge?" asks Omar looking out across the raging river."Let's start by finding the distance to the big rock on the other side."

Melissa replies. Moving 100 meters along the river, Melissa looks back and measures the angle between Omkar and the big rock: 33°. Melissa then instructs Omar to measure the angle between Melissa and the big rock.

From his vantage point, Omar sees an angle of 98° between Melissa and the big rock.