Jillian is a firefighter. She stands at an observation window 85 ft above the ground. From a distance, she spots a fire! She takes a reading -- and she sees that the angle of depression is 28∘. To the nearest tenth of a foot, how far away from the base of the tower is the fire?
Q. Jillian is a firefighter. She stands at an observation window 85 ft above the ground. From a distance, she spots a fire! She takes a reading -- and she sees that the angle of depression is 28∘. To the nearest tenth of a foot, how far away from the base of the tower is the fire?
Identify Relationship: Identify the relationship between the angle of depression and the angle of elevation.The angle of elevation from the base to Jillian's eyes is also 28∘ because angles of elevation and depression are congruent.
Use Tangent Function: Use the tangent function, which relates the opposite side (height of the tower) to the adjacent side (distance from the base of the tower to the fire).tan(28∘)=adjacentopposite=distance85
Solve for Distance: Solve for the distance by multiplying both sides by the distance and then dividing by tan(28°).distance=tan(28°)85
Calculate Distance: Calculate the distance using a calculator.distance = 85/tan(28°)≈85/0.5317≈159.9 feet