Download Lesson 4-1

Find a Missing Angle Measure
Use a trigonometric function to find the measure
of θ. Round to the nearest degree, if necessary.
Use a trigonometric function to find the measure
of Ө. Round to the nearest degree, if necessary.
A. 32°
B. 40°
C. 50°
D. 58°
Use an Angle of Elevation
SKIING The chair lift at a ski resort rises at an
angle of 20.75° while traveling up the side of a
mountain and attains a vertical height of 1200 feet
when it reaches the top. How far does the chair lift
travel up the side of the mountain?
AIRPLANE A person on an airplane looks down at
a point on the ground at an angle of depression of
15°. The plane is flying at an altitude of 10,000 feet.
How far is the person from the point on the ground
to the nearest foot?
A. 2588 ft
B. 10,353 ft
C. 37,321 ft
D. 38,637 ft
Use Two Angles of Elevation or
Depression
SIGHTSEEING A sightseer on vacation looks down
into a deep canyon using binoculars. The angles of
depression to the far bank and near bank of the
river below are 61° and 63°, respectively. If the
canyon is 1250 feet deep, how wide is the river?
Use Two Angles of Elevation or
Depression
Draw a diagram to model this situation. Because the
angle of elevation from a bank to the top of the canyon is
congruent to the angle of depression from the canyon to
that bank, you can label the angles of elevation as shown.
Label the horizontal distance from the near bank to the
base of the canyon as x and the width of the river as y.
HIKING The angle of elevation from a hiker to the
top of a mountain is 25o. After the hiker walks 1000
feet closer to the mountain the angle of elevation
is 28o. How tall is the mountain?
A. 3791 ft
B. 4294 ft
C. 7130 ft
D. 8970 ft
Solve a Right Triangle
A. Solve ΔFGH. Round side
lengths to the nearest tenth
and angle measures to the
nearest degree.
Solve a Right Triangle
B. Solve ΔABC. Round side
lengths to the nearest tenth
and angle measures to the
nearest degree.
Solve ΔABC. Round side lengths to the nearest
tenth and angle measures to the nearest degree.
A. a ≈ 44.9, b ≈ 82.7, A = 36°
B. a ≈ 40.3, b ≈ 82.7, A = 26°
C. a ≈ 40.3, b ≈ 85.4, A = 26°
D. a ≈ 54.1, b ≈ 74.4, A = 36°
THE END