Hi I was wondering if someone know how to do this I did it but a long time ago and now the teacher wants me to do corrections to improve my grade

The question that is asking is find the width of the rock formation AB

If someone could help me to start and give me steps or the process of how to do it I will really appreciated

Hi I was wondering if someone know how to do this I did it but a long time ago and now the teacher wants me to do corrections to improve my grade The question t class=