Download angle of depression

Angles of Elevation & Angles of Depression
The angle of elevation is the angle between a horizontal line from the
observer and the line of sight to an object that is ABOVE the horizontal
line.
The angle of depression is the angle between a horizontal line from
the observer and the line of sight to an object that is BELOW the
horizontal line.
Solving word problems involving angles of elevation & depression.
1) Read the problem and visualize what it looks like. Then draw a sketch
and label the known values (side lengths, angles, etc.). The triangle
should be drawn to scale. It is normally a right triangle.
2) 2Use trig
functions
(sin, cos, or tan) and the Pythagorean theorem
2
2
(a + b = c-1 ) to find
the
length of missing sides (sin θ, cos θ, tanθ) or
-1
-1
angles (sin , cos , tan ).
3) Solve for the missing part. Put units on the answer. Sides of the
triangle are lengths (feet, km, etc.) and angles are measured in
degrees.
John wants to measure the height of a tree. He walks exactly 100
feet from the base of the tree and looks up. The angle from the
ground to the top of the tree is 33º . How tall is the tree?
A building is 50 feet high. At a distance away from the building,
an observer notices that the angle of elevation to the top of the
building is 41º. How far is the observer from the base of the
building?
An airplane is flying at a height of 2 miles above the ground. The
distance along the ground from the airplane to the airport is 5
miles. What is the angle of depression from the airplane to the
airport?
A bird sits on top of a lamppost. The angle of depression from
the bird to the feet of an observer standing away from the
lamppost is 20 degrees. The distance from the bird to the
observer is 25 meters. How tall is the lamppost?
A tight-rope walker is going to walk between two buildings. One
building is 100 feet high. The other building is 140 feet high. If
the angle of elevation from the top of the shorter building to the
top of the taller building is 8 degrees, how long of a wire would it
take to reach from the edge of one building's roof to the other's?