Questions: Use the Law of Sines or the Law of Cosines to solve each triangle.
Round all angle measures to the nearest tenth of a degrees and side
Given? SSS
Use: Law of Cosines
Triangle
B= degrees
C= degrees
Transcript text: Use the Law of Sines or the Law of Cosines to solve each triangle.
Round all angle measures to the nearest tenth of a degrees and side
Given? SSS
Use: Law of Cosines
Triangle
B= degrees
C= degrees
Solution
Solution Steps
Step 1: Find angle B using the Law of Cosines
We are given a triangle with sides a = 8 in, b = 18 in, and c = 12 in. We can use the Law of Cosines to find angle B.
b² = a² + c² - 2ac * cos(B)
18² = 8² + 12² - 2 * 8 * 12 * cos(B)
324 = 64 + 144 - 192 * cos(B)
324 = 208 - 192 * cos(B)
116 = -192 * cos(B)
cos(B) = -116/192
B = arccos(-116/192)
B ≈ 127.2°