1. Law of Sines Standard: G.SRT.11
10/11/13
Law of Sines Standard: G.SRT.11
Essential Question: How do we use Trigonometry with acute and obtuse triangles

2. The Trigonometric ratios you have seen so far
in this Chapter can be used to find angle and
side measures in Right Triangles.
You can use the Law of Sines to find angle
and side measure in ANY triangle.

3. Law of Sines
𝒂 𝐬𝐢𝐧 𝑨 = 𝒃 𝐬𝐢𝐧 𝑩 = 𝒄 𝐬𝐢𝐧 𝑪 a C B c b A

4. Practice 1
Given that one angle of a triangle is 120 deg, another angle is 40 deg, and the side opposite the 40 deg angle measures 12 meters, find the side opposite the unknown angle.

5. Practice 2
Find the length of side b c
1200 b
350
10.45 cm

6. Practice 3
How much closer, to the nearest hundredth mile, does Jimmy lives
To school than Carlos?
School
1020 y x
170
Jimmy
Carlos
3 mi

7. Practice 4 The angles of a triangle are in a ratio of 4:5:8
The shortest side measures 2.65 inches. Find the
Length of the longest side to the nearest hundredth.

8. Homework
Text Book
Page 491: # 1, 2, 3
Have a nice weekend….

9. Practice 5
Use the Law of Sines to solve the triangle. Round decimal answer
To nearest tenth. C b 18 A
510 17 B