5.3 Angles Greater than 90 & The Cast Rule.notebook
Movember 1st, 2013
November 01, 2013
5.3 Exploring Trig Ratios
for Angles Greater than 90o
When drawing right triangles we will be placing all of these triangles on the coordinate grid.
The angles are always measured counterclockwise relative to the x‐axis. The portion of the angle that lies on the x‐axis is known as the initial arm, while the other arm that forms the angle is known as the terminal arm. The two arms make a connection at the origin (0, 0).
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5.3 Angles Greater than 90 & The Cast Rule.notebook
November 01, 2013
Every angle can be represented by the angle itself (which is known as the principal angle) as well as a relative acute angle, which is measured relative to the x‐axis.
Ex. The following is a principal angle of 115o, determine the relative acute angle associated with that angle.
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5.3 Angles Greater than 90 & The Cast Rule.notebook
November 01, 2013
Ex. Draw the following principle angles and determine the relative acute angle associated with each.
a) 206o
b) 322o
c) 87o
d) 154o
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5.3 Angles Greater than 90 & The Cast Rule.notebook
November 01, 2013
Ex. Calculate the primary trigonometric ratios for each of the principal and relative acute angles listed below.
of
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5.3 Angles Greater than 90 & The Cast Rule.notebook
November 01, 2013
Assigned Work:
pp. 5‐7 #2 ‐ 5 ace, 7, 10, 11, 17
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