for this question the required one is the distance b/n the light house and the boat (x) so in this case we are gonna use tan= opposite / hypotenuse :
- tan 20 = 89/ x (tan 20 is equivalent to 0.3640)
- 0.3640 = 89 / x
-x = 89 / 0.3640
- x = 244.5 ft. and when estimated x= 245 ft.