Question

Exercise 41

Answer 1

Answer:

514 m = width of the river to the nearest meter

Step-by-step explanation:

You must memorize the definitions of the trig functions and then these types of problems are easy.

You have a right triangle where the 100 m is the adjacent side to the 79° angle.  You are looking for the side opposite the 79° angle.  So, you need to use the tan function which is defined as opposite side/adjacent side

Let x = the length of the opposite side (width of river)

Tan 79 = x/100

100 tan 79 = x

x = 514 m = width of the river to the nearest meter