Sullivan Algebra and Trigonometry: Section 9.2

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Sullivan Algebra and Trigonometry Section 9.2

• Objectives of this Section
• Solve SAA or ASA Triangles
• Solve SSA Triangles
• Solve Applied Problems

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If none of the angles of a triangle is a right
angle, the triangle is called oblique.
To solve an oblique triangle means to find the
lengths of its sides and the measurements of its
angles.
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FOUR CASES
CASE 1 One side and two angles are known (SAA or
ASA).
CASE 2 Two sides and the angle opposite one of
them are known (SSA).
CASE 3 Two sides and the included angle are
known (SAS).
CASE 4 Three sides are known (SSS).
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The Law of Sines is used to solve triangles in
which Case 1 or 2 holds. The Law of Sines is
used to solve SAA, ASA or SSA triangles.
Law of Sines
5
c
b
5
6
b
12
a
7
3
a
5
8
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Two triangles!!
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Triangle 1
11
Triangle 2
12
3
5
a
No triangle with the given measurements!