Transcript Trigonometry Bits and Pieces - Maths-with-MsG

Trigonometry Bits and Pieces
Senior 3 Accelerated
Bearings and Trig.
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Remember that a bearing is an angle,
that is measured FROM NORTH in a
CLOCKWISE direction.
Bearings Question
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Town A is 20km north of Town B and
Town C is 45km west of Town B.
What is the bearing of A from C?
Angles of Elevation &
Depression
An angle of elevation is a
rising angle taken from a
horizontal line.
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An angle of depression is a
lowering angle taken from a
horizontal line.
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Angle of Elevation Question
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The angle of elevation from a buoy in
the sea to the base of a lighthouse on
top of a cliff is 25o. If the buoy is 750m
out from the base of the cliff, work out
the height of the cliff.
Angle of Depression Question

Two hot air balloons are connected by a
rope 12 m long. One balloon is 3m
higher from the ground than the other.
Work out the angle of depression from
the higher balloon to the lower balloon.
Two special triangles
Finding the distance between
two points.
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How can we work out the shortest
distance from (2,3) and (5,7)?