Easy Tri Math worksheets

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Math 1083 Worksheet 14 Getting Ready for Solving Oblique Triangles – the Law of Cosines

Objectives:

1. Solve trigonometric equations

2. Review the Pythagorean identities

3. Simplify expressions following PEMDAS

4. Identify SSA, AAS, SAS, SSS triangles

#1 Find all solutions on the interval 0° ≤ 𝜃 ≤ 180° Give all answer in degrees.

a) 2 sin 𝜃 − 1 = 0

c) −2 𝑠𝑖𝑛 θ + √3 = 0

b) 2 cos θ – √3 = 0 d) 2 cos θ + 3 = 2,

#2. Simplify the expressions.

a) 42 + 102 − 2(4)(10) cos 60° b) 102 = 52 + 62 − 2(5)(6) cos 𝜃 Do NOT solve.

#3. Solve the equation below for 𝑎. 𝑎2 = 72 + 82 − 2(7)(8) cos 45°

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Six types of triangles based on given information

#4. Determine which type of triangle is given in each case. Draw a diagram to illustrate. Do NOT solve

the triangles.

a) 𝑎 = 4, 𝑏 = 5, 𝑐 = 8 b) 𝑎 = 23.1, 𝑏 = 20, 𝐴 = 34°

c) 𝑎 = 6, 𝑐 = 8, 𝐵 = 40° d) 𝐵 = 35°, 𝐶 = 55°, 𝑎 = 12

e) 𝐴 = 75°, 𝑏 = 8, 𝐶 = 20° f) 𝑏 = 12, 𝑐 = 16.5, 𝐴 = 65°