Friday

September 19, 2014

September 19, 2014

Posted by **Laurianne** on Tuesday, January 19, 2010 at 6:25pm.

- Trigonometry -
**bobpursley**, Tuesday, January 19, 2010 at 6:34pma^2=b^2+c^2-2bcCosA

CosA= 1/2 * (b^2+c^2-a^2)/bc

A= 139 deg, you are right on that.

Lets find angle B, by the law of sines

sinB/b=SinA/a or sinB= .3269 or B=19 deg

Lets find angle C by the law of sines

SinC/c=SinA/a or SinC=.3718 C=21.8 deg

check: do the sum of angles = 180 deg?

139+21.8+19=180 rounded.

All is well.

**Answer this Question**

**Related Questions**

trigonometry (repost) Mathmate - I want to start by saying thank you . You have ...

Trigonometry - Find all the solutions of the following triangle using the Law of...

Physics (maybe it's just math) - A sphere of copper is subjected to 89.7 MPa of ...

Summer School Calculus - Add the following vectors , 7m/s [N30E] and 2m/s [S17E...

Math (trigonometry) - A surveyor wishes to find the height of a mountain. He ...

Trigonometry/Geometry - Law of sines and cosines - In most geometry courses, we ...

trigonometry - Use logarithms and the law of tangents to solve the triangle ABC...

trigonometry - okay so i have this trigonometry problem were i HAVE to use ...

Calculus - Posted by MG on Wednesday, March 26, 2014 at 6:54pm. The hands of a ...

Physics - A 1.8 tonne railway truck moving at a speed of 3m/s up a steady ...