Question

Find the measure of angle B​

Answer 1

Explanation:

Use the Law of Cosines for this. If we want the measure of angle B, then the equation is set up like this:

`b^2=a^2+c^2-2accosB`

Filling in:

`9^2=14^2+6^2-2(14)(6)cosB` and simplifying a bit:

81 = 196 + 36 - 168cosB and a bit more:

81 = 232 - 168cosB and even more:

-151 = -168cosB and divide both sides by -168 to get

.9378881988 = cosB

Now use the 2nd button on your calculator along with the cos button to find the missing angle. Make sure your calculator is in degree mode first. Your angle should be 20.30012152