Unformatted text preview: of inclination (from object to observer)
will be congruent because they are alternate interior angles.
(b) From a ﬁretower 200 feet above level ground in the Sasquatch National Forest, a ranger
spots a ﬁre oﬀ in the distance. The angle of depression to the ﬁre is 2.5◦ . How far away
from the base of the tower is the ﬁre?
9. From the observation deck of the lighthouse at Sasquatch Point 50 feet above the surface of
Lake Ippizuti, a lifeguard spots a boat out on the lake sailing directly toward the lighthouse.
The ﬁrst sighting had an angle of depression of 8.2◦ and the second sighting had an angle of
depression of 25.9◦ . How far had the boat traveled between the sightings? 10.3 The Six Circular Functions and Fundamental Identities 651 10. A guy wire 1000 feet long is attached to the top of a tower. When pulled taut it makes a 43◦
angle with the ground.
(a) How tall is the tower?
(b) How far away from the base of the tower does the wire hit the ground?
11. Verify the following identities. Assume that all quantities are deﬁned.
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