posted by Lili on .
A surveyor measures the distance across a
straight river by the following methods: Starting directly across from a tree on the opposite
bank, she walks 249 m along the river bank to
establish a baseline. Then she sights across to
the tree. The angle from her baseline to the
tree is 38.2
How wide is the river?
tan 38.2 = d /249
d = 249 tan 38.2 = 196 m