The Law of Cosines
The Law of Cosines – Example 2:
\(b=20, a=8, c=14\)
\(cos B= \frac {14^2+8^2-20^2}{2(14)(8)} =\frac {196+ 64 – 400}{176}=\frac{-140}{224}=-0.625\)
Since \(cosB\) is negative, \(B\) is an obtuse angle.
\(B≅128.69 ^\circ \)
Exercises for the Law of Cosines
In the ABC triangle, find the side of c.
1.
2.
3.
- \(\color{blue}{31.12}\)
- \(\color{blue}{44.68}\)
- \(\color{blue}{21.49}\)
Original price was: $109.99.$54.99Current price is: $54.99.
Original price was: $109.99.$54.99Current price is: $54.99.
Original price was: $109.99.$54.99Current price is: $54.99.
Related to This Article
More math articles
- The Ultimate 7th Grade NJSLA Math Course (+FREE Worksheets)
- Calculating the Surface Area of Prisms and Cylinders
- Top Free Websites for FTCE General Knowledge Math Preparation
- 5th Grade Common Core Math FREE Sample Practice Questions
- How to Find the End Behavior of Polynomials?
- How to Solve Permutations and Combinations? (+FREE Worksheet!)
- 6th Grade NDSA Math Worksheets: FREE & Printable
- How to Solve Angles and Angle Measure? (+FREE Worksheet!)
- Top 10 ACT Math Prep Books (Our 2023 Favorite Picks)
- How to Prepare for the AFOQT Math Test?
What people say about "The Law of Cosines - Effortless Math: We Help Students Learn to LOVE Mathematics"?
No one replied yet.